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Indicators of syntactic complexity in adults with congenital moderate-to-severe hearing loss Nienke Stolk Student number: 0308498 August 2012 The Faculty of Humanities MA thesis, General Linguistics (20 ECTS) supervisor UvA: dr. J. de Jong assessor UvA: prof. dr. A.E. Baker supervisors VUmc: drs. E. Huysmans en dr. S.T. Goverts Abstract Purpose: In this thesis the syntactic complexity of the spontaneous speech of Dutch normal hearing (NH) and moderate-to-severe congenital hearing impaired (MSCHI) adults was studied. The aim of the study was to examine the differences in syntactic complexity in spontaneous speech in both groups, NH and MSCHI, using nominal, adverbial and relative subordinate clauses, and more specifically the clausal densities (average number of clauses per T-unit), as an indicator for syntactic complexity. Method: The spontaneous speech of 20 MSCHI and 10 NH adults was collected using a “favourite games or sport”- task (FGST) to elicit expository discourse. All samples were audio taped, transcribed and analysed, measuring syntactic complexity of speech by using MLU, MLU5L, clausal densities, % subordination type as measures for syntactic complexity. Errors and avoidance strategies were analyzed and ad hoc categorized. Compared to normal hearing adults syntactically less complex language, the uses of compensatory strategies to avoid complexity and more morpho-syntactic errors were expected to be observed in moderate-to-severe hearing impaired participants. Results: No significant differences were found on the complexity variables between NH and MSCHI adults in spontaneous speech. On average both MSCHI and NH produced an equal number of subordinate clauses, the same applied for the different types of subordination. However, interesting differences were found on the error rates between MSCHI and NH. MSCHI made significantly more morpho-syntactic errors within the subordinate clauses (including errors made both inside and outside the subordinate structure) than NH adults did. Only few example of avoidance strategies were found in the speech sample. Conclusion: Based on the outcomes of this study there seem to be no differences in the syntactic complexity in the spontaneous speech of MSCHI and NH adults. Possible explanations might lie in the experimental group, due to the limited size of the research and higher educational level of the MSCHI adults. Where static analysis could be applied it demonstrated no significant group differences. KEY WORDS: syntactic complexity, subordination, hearing impairment, adults, spontaneous speech, clausal density 2 Preface This Master's thesis forms the last part of the Master program General Linguistics of the Faculty of Humanities at the University of Amsterdam. The present investigation is part of an exploratory study on the effect of congenital hearing impairment on language performance in (young) adults, that is currently being conducted by Elke Huysmans at the VU medical centre, department KNO–audiology. The aim of that project is to obtain a differentiated description of the moderate-tosevere congenital hearing impaired (MSCHI) induced language deficits, which persist through (young) adulthood. In this thesis I studied the syntactic complexity of the spontaneous speech of Dutch normal hearing (NH) and moderate-to-severe congenital hearing impaired (MSCHI) adults. With this investigation I want to contribute to the limited scientific research on the characteristics of language and language problems that occur in adults. By providing insight in the problems that remain in hearing impaired adults’ production speech, I hope to contribute to the practical field of speech therapist who help hearing impaired children acquiring a full command of language. Special thanks goes to Elke Huysmans, my supervisor from the VU medical centre for inspiring me with the own PhD research on hearing impaired and giving me the opportunity to conduct research in an adjacent area within her project. Her knowledge in the field of hearing impairment and linguistics, and knowledge in the field of hearing and hearing impairment and methodological knowledge of Theo Goverts whom I also want to thank sincerely, were of great value and contributed to the creation of this thesis. Also thanks are due to my supervisor, dr. Jan de Jong, for his ideas, time and frequent help to get me back on track. Thanks also to the second reader, prof. dr. Anne E. Baker. Finally, I would like to thank my family and friends for their support during my study. For questions or remarks as a result of this thesis an email can be sent to: [email protected] Nienke Stolk, Amsterdam, August 2012 3 Table of Contents Page Introduction ............................................................................................................... 6 1 Language development of congenital sensorineural hearing impaired people .. 8 1.1 Congenital sensory neural hearing loss .................................................................. 8 1.2 Language acquisition with a moderate or severe hearing impairment ........................ 10 1.2.1 Language acquisition and linguistic performance in hearing impaired children ............. 12 1.2.2 Language performance in hearing impaired adolescents (and adults) ........................ 15 1.3 Summary and discussion .................................................................................... 19 2. Syntactic complexity ...................................................................................... 20 2.1 Acquisition of syntactic complexity ....................................................................... 20 2.2 Subordination ................................................................................................... 24 2.3 Measuring syntactic complexity ........................................................................... 26 2.3.1 Mean Length of Utterance ................................................................................... 26 2.3.2 Clausal densities ............................................................................................... 27 2.4 Research questions ........................................................................................... 28 2.5 Summary and discussion .................................................................................... 31 3 Method ............................................................................................................ 32 3.1 Participants ...................................................................................................... 32 3.2 Data collection .................................................................................................. 34 3.3 Analysis ........................................................................................................... 36 3.3.1 Syntactic complexity ......................................................................................... 37 3.3.2 Errors ............................................................................................................. 39 3.3.3 Avoidance of syntactic complexity and compensatory strategies ............................. 41 4. Results ............................................................................................................ 43 4 4.1 Results for syntactic complexity .......................................................................... 44 4.2 Results for error analysis .................................................................................... 46 4.3 Results for avoidance strategies .......................................................................... 48 5. Conclusion and discussion ............................................................................. 49 6. Bibliography .................................................................................................. 52 Appendix I: List of abbreviations used in this thesis and appendix II ................................ 59 Appendix II: Detailed information about the discussed studies......................................... 60 Appendix III: Research data ...................................................................................... 64 5 Introduction The present investigation is part of an exploratory study of the effect of congenital hearing impairment on language performance in (young) adults. In this thesis the syntactic complexity of the spontaneous speech Dutch moderate-to-severe congenital hearing impaired (MSCHI) adults is studied and compared to Dutch adults with normal hearing (NH). The thesis contains a literature review on research conducted on language development in congenital hearing impaired and the acquisition of syntactic complexity. It also contains an empirical part in which different types of subordinate clauses as they occur in spontaneous speech of normal hearing and moderate-to-severe congenital hearing impaired adults will be investigated. Different types of subordinate clauses are taken as an indicator for the syntactic complexity in spoken language. The language intake of hearing impaired individuals is partial and degraded which provides inadequate information, and gives the child an insufficient model of the language that has to be learned to (Delage and Tuller 2007). Davis et al. (1986) found that even minimal hearing loss places children at risk for language and learning problems, with regard to language production and language processing. Delage and Tuller (2007) examined the effect of hearing loss on language performance in adolescents finding that language does not normalize with age. Consequences of hearing loss on the language development in children and the acquisition of full language competence will be discussed in the first chapter of this thesis. Language impairment has been reported for children with hearing loss in the areas of phonology, vocabulary and morphology and syntax (Elfenbein et al., 1994; Moeller et al. 2007; McGuckian and Henry 2007). Several studies have explored the acquisition of syntax and syntactic complexity in children with hearing loss, but relatively few studies (Delage and Tuller 2007; Nippold et al. 2005; Nippold et al. 2008; Nippold, 2009) have examined the same linguistic aspects in hearing impaired adolescents and adults. These studies have given new insights on the importance of syntactic complexity as an indicator for the severity of the language impairment. Nieminen wrote: “Growth in complexity is perceived as an index of development in linguistic abilities and therefore, complexity is an essential concept in language acquisition studies” (Nieminen, 2009 p.173). A description of syntactic complexity and the development of syntax is necessary in order to understand the hierarchy of 6 syntactic complexity. Chapter 2 will give an overview of the most important, recent studies on syntactic complexity in hearing impaired children, adolescents and adults (Delage and Tuller 2007; Nippold et al. 2005; Nippold et al. 2008; Nippold, 2009). These studies will serve as a framework for the research done for this thesis, which will examine the differences in syntactic complexity in both groups, normal hearing and moderate-to-severe hearing impaired, using nominal, adverbial and relative subordinate clauses, and more specifically the clausal densities (average number of a clause type per T-unit), as an indicator of syntactic complexity. Based on the previous research of Nippold and Delage et al. research questions and hypotheses will be formulated about the syntactic complexity of spontaneous speech of hearing impaired adults (chapter 2.5), that will form the core of the empirical research. For the exploratory part of this thesis the spontaneous speech of normal hearing adults (N=10) and moderate-to-severe hearing impaired adults (N=20), elicited in expository discourse to challenge subjects to use as complex language as possible, is analyzed for syntactic complexity. The methodology and variables are described in chapter 3. To provide answers to the research questions addressed in this thesis a comparison between normal hearing and moderate-to-severe hearing impaired adults will be made on the complexity variables. These findings will provide results on the potential variance between the syntactic complexity for both groups. Results of this research will be presented in chapter 4 and this thesis will be concluded in chapter 5 with a discussion on the research as well as recommendations for future research. 7 1 Language development of congenital sensorineural hearing impaired people 1.1 Congenital sensory neural hearing loss Hearing is the ability to perceive vibrations in the air, captured by the ear drum in the outer ear, transmitted by the middle ear through the auditory bones into the basilar membrane in the inner ear, where the vibrations in the cochlea are converted into an electric discharge by the auditory nerve. These oscillations, sound waves, can vary in amplitude, frequency and phase, making a difference in the perception of sounds. This sensitivity to sound is not the same for everyone. On average, people are able to perceive sounds between 20 Hz and 20 KHz, the frequency of sound. The amplitude of the sound should be louder than the so-called hearing threshold for people to be able to perceive them. This threshold is displayed in decibels and differs per individual. The hearing threshold for normal hearing people is between 0- 20 dB. (Audiologieboek.nl (2009), chapter 2) Figure 1. The anatomy of the ear seen from a cross-sectional view (www.phonak.com) As shown in the picture above sound perception is a complex process, which requires that the outer, middle and inner ear are working properly. A problem in any 8 part of the ear can cause hearing problems; either a hearing disorder or hearing loss, that often accompany each other. There are two main forms of hearing loss that can be distinguished depending on which part of the ear is affected. The first form is sensory neural hearing loss, an inner ear problem, which means that sounds are not efficiently transmitted by the auditory nerve into the brain. The other form of hearing loss is conductive hearing loss, occurring because of a mechanical problem in the outer or middle ear, which is a result of some kind of obstruction in the system or amplifier that regulates the sound. Hearing loss can also be divided into congenital hearing loss meaning that the hearing loss is innate, and acquired hearing loss, appearing after birth, which is usually the result of aging. (Audiologieboek.nl (2009) chapter 1) The severity of hearing loss is expressed in decibels (dB), and is determined by measuring the hearing thresholds for different frequencies (250, 500, 1000, 2000 and 4000 Hz). The average hearing loss is calculated by taking the average value of the three most sensitive frequencies in the vocal area, the so-called Fletcher Index (FlI). The frequencies are 500, 1000 and 2000 Hz. The degree of hearing loss is, based on the number of decibels of hearing loss, overall classified into several categories, ranging from normal (0 dB) hearing to deafness. The overview below shows one of the more commonly used classification systems (Clark, 1981). -10 to 15 dB loss in the better ear = normal hearing 16 to 25 dB loss in the better ear = slight hearing loss 26 to 40 dB loss in the better ear = mild hearing loss 41 to 55 dB loss in the better ear = moderate hearing loss 56 to 70 dB loss in the better ear = moderately severe hearing loss 71 to 90 dB loss in the better ear = severe hearing loss more than 90 dB loss in the better ear = profound hearing loss Several researchers report that the degree of hearing loss is an important factor for language development of children with hearing problems (Bamford and Saunders 1999; Bench and Bamford 1979; Mogford 1993). Davis et al (1986) found that even minimal hearing loss places children at risk for language and learning problems, with regard to both the area of language production and the area of language processing. 9 1.2 Language acquisition with a moderate or severe hearing impairment This study focuses on the characteristics and the differences in syntactic complexity in oral language between hearing-impaired and normal hearing adults. Hearing loss is an important factor for language development (Bamford and Saunders 1999) and a risk for language and learning problems (Davis et al. 1986). Although in this thesis the focus is on hearing-impaired adults, it is very interesting to look at the language development of hearing impaired children. A logical assumption is that characteristics of (atypical) adult language production arise as a result of (atypical) language development. Do congenital hearing impaired children go through different or delayed language development compared to normal hearing peers as a result of their hearing loss? Which language areas are affected and in which areas problems will remain later in life? Results from studies of language development in hearing impaired children may explain if and why there are problems in certain language areas that may persist during adolescence and into adulthood. Therefore a review of studies on language development in mild-to-severe hearing impaired children and language of mild-to-severe hearing impaired adolescents and adults will be the subject of the following sections (respectively 1.2.1 and 1.2.2). However, firstly some general issues will be addressed. Young language learning children acquire language and speech by auditory environmental language input. Normal language learning occurs only when a child is exposed to language early in life. Children, regardless of language education, develop a vocabulary and learn to abstract the underlying structures and patterns that are inherent to their mother tongue from the auditory input, combining this pattern detection with their computational abilities and specific social (pragmatic) skills (Delage et al., 2008). Exposure beginning later in life, or absence or partial absence of early exposure to spoken language “may lead to life-long changes in the ability to learn language” (Kuhl 2004, p.831). Researchers suggest that natural language acquisition that is based solely on language input, unlike learning a second language through language input and language education, can only take place during ‘the’ critical period. The critical period hypothesis claims that the first years of life, the period from early-to-mid childhood (age 5 to puberty), is the ideal period for a child to acquire a first language in a linguistically rich environment (Lenneberg et al. 1967). In language development, “the effects over age of first exposure are approximately linear through childhood with a flattening of the function in adulthood” (Newport 1990, 20). These findings argue that maturational language-particular constraints, ensuring successful 10 language learning, exist early in life and are weaker with increasing maturation (Newport 1990). If the child is not exposed to auditory input or the stimuli are not adequate during the critical period, it will never achieve a full command of language. Based on this assumption it is clear that for good language development it is extremely important that during this critical period the language-learning child can fully benefit from the auditory language input. Thus, good hearing and an efficient way of processing auditory language input are essential for language development. This is a crucial point, which explains why in children with innate hearing loss problems in language acquisition (could) arise, problems that could persist in adolescents and adults. Kumaravadivelu (1994) describes the problem hearing impaired children are facing by making an important distinction between language input and language intake defining language input as the language that is directed or spoken in the environment of the child, whilst intake is what the child has processed/perceived from the input. Even if the environment is linguistically rich, children who are hard of hearing from birth, as previously described, have a language intake that is partial and distorted. This means that they have to learn a language during the critical period based on a poor(er) language intake. They cannot fully benefit from the auditory input due to their congenital hearing loss, unlike normal hearing children. The language-impaired child will be hampered by the hearing impairment, but also by the distorted acoustic signal, even if it is wearing hearing aids. The acoustic information is insufficient with respect to the language to be learned. This means that many children with mild-to-severe hearing loss are at risk for delayed language development (Davis et al., 1986; Mogford 1993; Bamford and Saunders 1999). Even after receiving hearing aids or cochlear implants a mildly, moderately or severely hearing impaired child tends to delay in spoken language. Several studies concerning language development in deaf and hard of hearing children show that there is large individual variation, but even the children with high language scores are behind normal hearing children when it comes to (spoken) language development (Norbury, et al.,2001; Elfenbein et al., 1994; Moeller 2007; Spencer and Marschalk, 2006; Svirsky et al., 2000). Research has shown that the severity of the hearing impairment in children is weak or even not related to scores on linguistic tasks (nor the age of detection) (Blamey et al., 2001, Norbury et al., 2001, and Gilbertson & Kamhi, 1995; Tuller & Jakubowicz, 2004; Friedmann & Szterman, 2006). The large individual differences thus cannot be attributed solely to the severity of the hearing loss (whether or not compensated by hearing devices), but also reflect differences in acquisition rate, maturational and environmental factors. 11 The same individual variation occurs in typical developing children, although their overall level of linguistic development is generally higher than for hearing impaired children. These individual differences continue along the critical period during adolescence and into adulthood (Nippold et al., 2005). 1.2.1 Language acquisition and linguistic performance in hearing impaired children Much research has been done on language acquisition and performance of children with severe to profound hearing loss, and less on mild-to-moderate (MMLH) and moderate-to-severe hearing loss (MSHL). Language impairment has been reported for children with hearing loss in the areas of phonology, vocabulary, morphology and syntax. Moeller et al (2007) give an overview of the research regarding the development of language and literacy in children with mild-to-severe hearing impairment. Because of language development in hearing impaired children is much more studied than the language of adolescents and adults it is a great source of information about the characteristics of language impairment that also could go for adolescents and adults. Cross-sectional on language acquisition in hearing impaired children can lead to predictions about the language of hearing impaired adults. In this review the focus will be on the acquisition of spoken language and language domains that are acquired later in language development and cause problems that even remain clearly visible after the critical period into adolescence and adulthood. From birth the language intake of the hearing impaired child is partial and distorted from the input they get from their environment. Their quality and the extent of their auditory-linguistic experience differ from normal hearing children (Moeller, 2007). Hearing impaired children are in different ways hampered by their diminished hearing. Because of their hearing loss, hearing impaired children miss certain sounds and syllables or perceive them distorted. The child imitates the language it perceives. The hearing, however, gives inadequate information about word forms and morphemes, and also insufficient information to adjust its own speech. This affects hearing impaired children’s phonological awareness, and cause problems with language production but also with language comprehension (Calvert, 1982). Hearing impaired children show poor productive (and receptive) vocabulary skills, and they slowly expand their vocabulary. From research on new word learning and 12 semantic development it can be concluded that word learning delay in mild-tomoderate hearing impaired children is highly related to difficulties in coding, storing and retrieving phonological information (Gilbertson & Kamhi, 1995; Norbury et al., 2001). The rate at which mild-to-moderate hearing impaired children learn new words is not linked to the severity of hearing loss, but is related to their phonological processing skills and phonological memory (Gilbertson & Kamhi, 1995). These phonological processing problems are to some extent related to the degree of hearing loss. Word repetition was observed to be directly related to the degree of average pure tone loss, no such relationship was found between novel word learning and degree of hearing loss (Briscoe et al., 2001). The effects of hearing impairment on phonological and vocabulary development are also seen in the development of morphology and syntax. Language learning children acquire their mother tongue by abstracting the morpho-syntactic rules from the language input they get. Because hearing impaired children do not perceive these often unstressed, but very important morphemes from their language input, as well as normal hearing children, hearing impaired children can have more difficulties to determine the morpho-syntactic rules of the language offered to them. Unstressed syllables or bound morphemes, often grammatical elements that mark rules like verb morphology (tense, agreement) and plural forms are difficult for hearing impaired children to observe and are serious obstacles to their development of morpho-syntax. This could lead to problems with language comprehension, but it also would have consequences for their language production (Elfenbein et al., 1994). These elements are indispensable for the acquisition (and production) of complex syntax. In most young children syntax emerges around the age of 16 months, when the first multi-word sentences are produced (Gillis en Schaerlaekens, 2000). In this first stage of syntactic language development, children form (mainly two word) sentences using the so-called build-up and break-down systems, with which they try their syntactic abilities (Gilles en Schaerlaekens, 2000 p. 22). This means that children extend their sentences by using separate words (or phrases) in varying combinations, resulting in primitive utterances that resemble telegraphic. This telegraphic phase is a multi-word phase, which is characterized by short sentences, which contain little or no function words, and do not have morphology. From this stage on, sentences refine and expand, which means they will consist of more words (nouns, verbs, determiners, conjunctions etc.) with appropriate morphology and within increasingly complex syntactic structures. This means that the early stages of language development are characterized by the appearance of new structures while 13 language in later life is characterized by the appearance of combinations of different syntactic structures that were acquired at a younger age, now resulting in complex syntax (Gillis en Schaerlaekens, 2000). For many young children the acquisition of complex (morpho-)syntax appears to be effortless (Marinellie, 2004), but it is clear that as a result of their hearing loss, hearing impaired children are at increased risk, compared to normal hearing children, for having delay in the acquisition and problems in use of (complex) morpho-syntax. Studies on morpho-syntactic development in children with hearing impairment (especially mild-to-moderate hearing impaired) are relatively recent and research findings in this area are varied. Bol and Kuiken (1988) investigated the spontaneous language production of a group of Dutch children (age 3;0-9;0) with moderate-to-severe hearing loss. On the morphological level, there was a low production of articles, function words, pronouns, copula, and auxiliary verbs. The children made many errors in verb inflection, especially in the present singular and past simple. Plural morphology in nouns was at the same level as their hearing peers. These results can be compared to those of Bamford and Bench (1979) in their study of English-speaking children. Norbury et al. (2001) found that English mild-tomoderate hearing impaired children do not have more difficulty than normal hearing children with verb conjugations (tense and/ or agreement), although a subset of hearing impaired children showed problems with past tense (for example regular walk/ walked and irregular give/gave) and singular –s (he drink(ø) lemonade). These results (Bamford and Bench, 1979; Bol and Kuiken, 1988; Norbury et al., 2001) suggest that mild-to-severe hearing impaired children may have problems mastering verb morphology. McGuckian & Henry (2007), studying the production accuracy of grammatical morphemes (GM) in spontaneous language production of children with mild-tomoderate hearing loss, found significant differences in grammatical morpheme production between a mild-to-moderate hearing impaired and a normal hearing Mean Length of Utterance (MLU)-matched control group. Not only is there a delayed morphological development in mild-to-moderate hearing impaired children, but the application of the morphological rules is also less accurate. The order of grammatical morpheme accuracy for the mild-to-moderate hearing impaired group was characteristic of that reported for second language learners of English. Findings of Elfenbein et al. (1994) suggested that the frequency of grammatical errors was related to the degree of hearing loss. Overall patterns of development they observed in 40 mild-to-moderate hearing impaired children seemed to be similar to typically developing children but the hearing impaired children were, whether or not seriously, 14 behind. Error rates were higher for moderate-to-severe congenital hearing impaired children than in typically developing children, with most errors (most of them omissions) made in complex syntax, verb structures, bound morphemes and pronouns. In Dutch moderate-to-severe hearing impaired children Bol and Kuiken (1988) found a lower Mean Length of Utterance for hearing impaired children than for their normal hearing peers. Bol and Kuiken observed a delay for morphosyntactic structures that increased as it came to structures from later acquisition stages. Moderate-to-severe hearing impaired children continued to (over)produce syntactic structures from earlier developmental stage and produced significantly less complex structures; e.g. structures containing more than 4 phrases, and coordination. 1.2.2 Language performance in hearing impaired adolescents (and adults) Recent research has examined the same linguistic aspects as described in section 1.2.1, but than in hearing impaired adolescents and adults (Delage 2007; Hamann et al. 2007; Delage & Tuller 2009; Tuller et al. 2012). The limited number of investigations done into the lasting effects of hearing impairment in older people show that the language areas affected in younger children to a greater or lesser extent also create problems for adolescents and adults. These studies have provided four main new insights and will be discussed below. The first important finding was observed by Delage and Tuller (2007), who examined the effect of hearing loss on language performance in adolescents (N=19, age 11-15) with mild-to-moderate (21 to 70 dB) hearing loss, questioning if language (generally or in certain areas) normalizes with age. In normal hearing people in the area of phonology and morpho-syntax, most linguistic skills are acquired by the age of 12 (Lenneberg et al., 1967). The results of Delage and Tuller (2007) research showed that more than half of the adolescents with mild-tomoderate hearing loss participating in this study had particular difficulties in phonology and morpho-syntax. The scores of mild-to-moderate impaired participants were significantly lower than those of typically developing controls on grammatical judgement, expressive grammar (French clitics) and phonology. Scores in these areas were highly correlated. Oral comprehension, written language and vocabulary seemed to be relatively unaffected. Language impairment in morpho-syntax and phonology was related to severity of hearing loss in this study (p<.05). No correlation could be established between age and hearing loss detection or age of 15 hearing aid fitting and language performance. No significant correlation was found between language scores and age or for language scores and nonverbal intelligence. The latter suggests that it does not seem to be the case that intersubject variation could be explained by something like general intelligence. Delage and Tuller (2007) concluded that language impairment thus is not resolved in hearing impaired adolescents and that there is no normalization with age. Indeed, while a negative effect of hearing loss was observed in children, but correlation for the severity of their hearing loss on their language performance was not observed, correlation between average hearing loss and performance in morphosyntax and phonology was found for adolescents. Delage and Tuller (2007, p.1300) concluded that this effect, only found after childhood “might be because linguistic development is basically complete after adolescence”) and the fact that this tendency was not observed in children can be declared by the “developmental rhythms that vary from child to child”. Although the effects of hearing loss in children are visible, it is difficult to link language problems to the severity of hearing loss and to predict to what extent these problems persist at the end stage of language acquisition. In adolescents and adults, the effect of the end of the critical period is visible. The main and lasting effects of hearing loss can clearly be identified, because they have reached the (almost) final stage of language development. This makes (young) adults an interesting research group to study, because it may reveal and give clearer insights in persistent language problems arising early in language development and remaining after the critical period into adolescence and beyond. Secondly, consistent with the observation of language not normalizing with age, the studies of Delage and Tuller (2007 and 2009) and Delage et al. (2008) seem to show that the remaining problems in mild-to-moderate hearing impaired adults persist particularly in morpho-syntax, and seem to lie mostly in the last acquired most complex structures of language. Similar results were found for adolescents with specific language impairment (see Tuller, et. al 2012; Hamann, 2007; Marinellie, 2004). Delage et al. (2008) studied morpho-syntax in French adolescents, focussing on relative clause acquisition in atypical acquisition of French. They argued that, apart from movement, other factors such as distance, but moreover depth of embedding play a role for complexity. Children and adolescents start with shorter movement, producing subject relatives and so-called pseudorelatives, which are relative constructions that involve lees deeply embedding clauses. They avoid movement (non-subject relatives) and computations which involve deeper embedding (genuine relatives). Analysis of this order of acquisition shows that the first embeddings subjects make are shallower, which make them less 16 complex. Research shows that relatives which involve less embedding and complexity and are (therefore) predominant in early developmental stages of language learning typically developing children and also in some stages of atypically developing children. The mean number of relative clauses produced is significantly lower in mild-to-moderate hearing impaired children (the same is observed in children with specific language impairment) than in the typically developing agematched children and adolescents. The rate of embedding increases with age, and varies according to the severity of the impairment. The research emphasises the link between computational complexity and the acquisition of relative clauses in typical and atypical contexts. They consider complexity to be a linguistic concept, which refers to syntactic movement and the depth of embedding (this will be discussed in section 2.1). Delage and Tuller (2009) focussed on the development of syntactic complexity. First time testing (T1) results showed that among subordinate clauses, mild-tomoderate hearing impaired children and adolescents produced fewer relative clauses than typically developing children. Comparison of the two age groups showed that the younger mild-to-moderate hearing impaired subjects used less complex syntax than older mild-to-moderate hearing impaired subjects. They produced less deeply embedded clauses, more 0-level relatives and more non-finite embedded clauses than older mild-to-moderate hearing impaired and typically developing children and adolescents. Rate of embedding and MLU did not improve between T1 and T2. The second testing point (T2) showed an increase of complex structures. Younger mildto-moderate hearing impaired subjects caught up adolescents with mild-to-moderate hearing loss but their final performance remained lower than typically developing subjects. Besides the overall lower level of syntactic complexity in hearing impaired adolescents another interesting finding was observed. Analyses of spontaneous speech samples of atypically developing (children and) adolescents indicated behaviours of avoidance of complexity by low production of complex structures, but also by high frequency of failed attempts and alternative strategies, like direct speech (Delage et al., 2008; Delage and Tuller 2009; for SLI see Hamann et al, 2007; Tuller et al. 2012). Instead of complex, subordinate clauses it was observed that atypically developing adolescents used more direct speech (see example a) or coordinated (juxtaposed) simple clauses (see example b) where they could have used a main complex clause (Delage and Tuller 2009; for SLI see Hamann et al, 2007; Tuller et al. 2012). In the examples the subordinate sentences are placed between brackets. 17 a) direct speech: I) You can say: “I want it faster.” instead of You can say [that you want it faster]. b) juxtaposition of two clauses instead of subordination: I) I saw his friend he is nice, in stead of I saw his friend [who is nice]. c) self-interruption of a subordinate clause: I) Well, she is the girl [that…] … she is interested in sports games II) I think [that he... she yelled because] ... Self-interruptions (example c) were observed to appear often in the spontaneous speech of mild-to-moderate hearing impaired adolescents, more than in normal hearing adolescents. In some cases of self-interruption the subordinate clause was really abandoned (c I), where other self-interruptions were followed by a correct subordinate clause (c II). In the first form of self-interruption it is clear that a subordinate clause is aborted, and replaced by a main clause. For this example the use of the term avoidance is appropriate. The second one is definitely not a form of failed attempt, bur probably the result of self-correction. Researchers (Delage and Tuller 2009; for SLI see Hamann et al, 2007; Tuller et al. 2012) do not distinguish between the different forms of self-interruption, all calling them avoidance. This makes this category ambiguous and less suitable to make statements about avoiding complexity. If complex subordinate sentences are harder to produce, it is likely that in these syntactically complex sentences more errors will be made, especially in morphosyntax, than in simple(r) sentences. High error rates, indeed, are found in children with mild-to-moderate hearing loss (Elfenbein et al., 1994), and remained very high in adolescents (Delage and Tuller, 2009). There results showed that 21% of complex utterances produced by all participants were erroneous versus 3% of those produced by typically developing subjects (p <.001). And among the different types of subordinate clauses, relative clauses were the most erroneous embedded clauses 18 (37% versus 19% erroneous finite complement clauses, 20% adverbial clauses). The types of errors are not further specified in the research of Delage and Tuller (2009). Tuller et all. (2012) who did similar research studying avoidance of complexity and errors in spontaneous speech of adolescents with specific language impairment. All morpho-syntactic errors were coded for syntactic category affected (root clause, finite complement clause, non- finite complement clause, adverbial clause, relative clause, or coordinate clause) and type of error (omission, addition, substitution, word order). A higher percentage of complex clauses was erroneous when compared to simple clauses, containing no subordination. These findings are consistent with the expectation in syntactically complex sentences more errors will be made. Errors in complex structures frequently entail avoidance of complexity. Avoidance of complexity could also result in the use of generally simpler structures, which increases the chances of production of error-free utterances. Tuller et al. (2012) conclude that language patterns consisting of error rates but also frequency of occurrence of complex structures and other avoiding strategies (e.g. direct speech) in atypical populations can therefore provide evidence for lesser syntactic complexity. 1.3 Summary and discussion Sensorineural hearing loss entails not only lowered thresholds, bur also distortion of the sound input. This results in language and speech recognition and understanding that is partial and degraded. If a child is not exposed to auditory input or the stimuli are not adequate during the critical period, it will never achieve a full command of language. This means that many children with mild-to-severe hearing loss are at risk for delayed language development, even after receiving hearing aids. Summarizing the studies discussed in the previous sections, we can conclude that language problems arise in all language areas (phonology, vocabulary, morphology and syntax) in mild-to-severe hearing impaired children, problems that remain into adolescence and adulthood. This means that language does not normalize with age (Delage and Tuller, 2007). The biggest problems occur in the most complex structures that are acquired during the latest stadium of language development (Delage and Tuller, 2007, 2009; Delage et al., 2008). Analyses of spontaneous speech samples of atypically developing (children and) adolescents indicated behaviours of avoidance of complexity by low production of complex structures, moreover in which more errors were made than in simple sentences. 19 Adolescents but also by high frequency of aborted sentences, failed attempts and alternative strategies, like direct speech (Delage et al., 2008; Delage and Tuller 2009; for SLI see Hamann et al, 2007; Tuller et al. 2012). These findings provides support for the hypothesis that mild-to-severe hearing loss has persistent effects on language acquisition, and that these effects result in reduced syntactic complexity: less frequent use of complex structures (whether or not by use of avoidance strategies) and in higher error rates in complex structures compared to typicallydeveloping children and adolescents. 2. Syntactic complexity The previous chapter shows that hearing impairment can have major consequences for language acquisition in all linguistic areas. There is no normalization of language performance in adolescents with mild-to-moderate hearing loss; more than half of the mild-to-moderate hearing impaired adolescents displayed relatively severe long-term language impairment. These problems especially persist in (morpho-)syntax, and seem to lie mostly in the last acquired most complex structures of language. Syntactic complexity especially seems a sensitive indicator for (persistent) language problems. The purpose of this chapter is to give a theoretical description of the term syntactic complexity and how this can be measured. This disquisition will be the foundation of my own empirical research as will be described in Chapter 3. 2.1 Acquisition of syntactic complexity Generally in the literature, language development and syntactic growth are related to syntactic complexity. “Growth in complexity is perceived as an index of development in linguistic abilities and therefore, complexity is an essential concept in language acquisition studies” (Nieminen, 2009 p.173). During language development children acquire syntactic structures that help them produce longer, refined and more complex sentences. The knowledge of syntax increases rapidly during the critical period, at the end of which all syntactic rules have to be obtained. Studies that focus on language development have assumed that simpler structures are acquired earlier in language development and that complex structures are acquired later or cause long-term difficulties (Nippold et a., 2007; Smith 1988; Smith and van Kleeck 1986; Hamann et al., 2007). In other words, this could mean that the order of development can be identical to the order of complexity. In this section and section 2.2 on subordination this issue will be addressed 20 With the emergence of finiteness, morphological rules (tense and agreement) interact with syntactic rules. This expansion of syntactic abilities enables children to express themselves better and more versatile. This goes along with overall maturation of linguistic development (e.g. vocabulary expansion) and the development of pragmatic rules. As their vocabulary and morphology increase and children have more word forms and categories available (articles, question words, conjunctions) their sentences become longer and more complex. In order of acquisition children start to use main clauses, interrogative sentences, coordinations and finally subordinations (Gillis and Schaerlaekens 2000). Syntactic constructions that emerge later in typical language development and also emerge more slowly and/or cause problems in mild-to-moderate hearing impaired children and adolescents can be characterized by a degree of higher computational complexity (Hamann et al., 2007; Nippold et al., 2007), as will be discussed later in this section and in section 2.2. Because of the increased linguistic knowledge (vocabulary, morphology, syntax) and knowledge of the world, older children, adolescents or adults can express their thoughts and experiences with more complex words and phrases. Conversational turns, for example, become longer (duration); sentences may consist of more communicative words, they may contain combined syntactic structures (conjunction, embedding), and have different word orders or contain movement. Compare the sentences presented in table 1. Table 1. Four categories of the main sentence types, ascending in syntactic complexity (Marinellie, 2004; Nippold et al., 2007; Nippold, 2010). 1. simple clauses i. Yesterday I went to see Marie. 2. coordinate clauses i. I went to her house, [but she was not at home]. 3. complex (subordinated) clauses i. [She was walking her dog], when it started to rain. ii. [She was walking her dog], which she got for her birthday. 4. combined complex clauses i. It is a very nice dog [that wags its tail], [whenever you stroke him]. 21 Simple (main/ root) clauses are the simplest type of sentences, containing (at least) a verb and a subject. A coordinate clause, often referred to as a compound clause, is a sentence that does not have embedded clauses, but at least two main clauses joined by a coordinate conjunctions, including but, and, so and or (for example but, see table 1, example 2.i). Complex clauses are sentences that contain one main/ independent clause and at least one dependent clause, meaning that they contain subordination. Combined complex clauses consist of the most complex syntactic structures, being a combination of the sentence types mentioned above: compound and complex combined or complex in complex, meaning a dependent clause is embedded in another dependent clause. A complex hierarchy of clauses, or syntactic complexity then occurs. When a subordinated clause is embedded in another subordinated clause, which is embedded in a main (simple) clause, a hierarchy of clauses occurs. The hierarchy is based on the levels of embedding. In determining levels of embedding, all finite verbs in a sentence represent a clause (Nippold, 2010). This means that from the sentences in table 1 example 1) contains one clause, 2) contains two (independent) clauses, 3) contains two (1 independent and 1 dependent) clauses, 4) contains three clauses (1 independent, and 2 dependent). Note that there is not only a difference between the number of clauses within these examples, but also in clause dependency. Referring to table 1, 3) the complex clause, has 1 level of embedding consisting of one main and one subordinate clause whereas 4) has 2 levels of embedding, one main with an embedded clause, with an embedded clause in it. These latter two are examples of one T-unit (which more extensively will be discussed in section 2.3.1) consisting of a main clause and (one or more) subordinate clause(s) (Scott, 1988). It seems logical that (most) errors will occur in spontaneous speech in the most complex sentence types. These errors may lie in the field of dependencies themselves, but also in complementizers mistakes or omissions, word order errors, and lead to simplification and less computational complex (whether or not ungrammatical) language (Hamann, 2007). Delage and Tuller (2009, p.2) state that ‘computational complexity’, within a generative framework, can be characterized by three main factors set out in table 2. 22 Table 2. Three main factors of computational complexity by Delage and Tuller (2009, p.2). • the number of syntactic operations : ‘with the number of merges and presence or absence of movement’ • the nature of syntactic operations: ‘merge versus movement, distance of dependency relations and/or the nature of intervener in such relations.’ • the depth of embedding: …’deeply embedding constituents increase the cost of the syntactic computation’ With ‘merge’ is meant the operation when two syntactic objects are combined to form a new syntactic unit (Chomsky, 2001). This is divided into external merge when the entities are two separate objects and internal merge when one of them is part of the other. Movement as explained by Carnie (2006) is the fact that certain constituents appear to have been displaced from the position where they receive important features of interpretation (for example movement of the subject or the object to preverbal position in interrogatives). With depth of embedding means subordinate clauses embedded in main clauses for different levels (Nippold, 2010). Compare the following two examples (5 and 6): 5) I take a card. 6) You can ensure [that a person [who has only one card] has to take a card]. In sentence 6 compared with sentence 5 we see a much more complex sentence structure, involving: - merge: which in sentence 5 for example exists of the verb selecting a subject and an object, whereas the main verb in sentence 6 selects a subject and a direct object in the form of a nominal subordinate clause that has the function of a noun phrase. - movement: Sentence 5 is a simple clause that does not involve movement. In sentence 6 the Wh-word (who) used in relative clauses is moved to the front of the clause. 23 - depth of embedding: sentence 5 only consists of one main clause, whereas sentence 6 consists of a main clause, a nominal subordinated clause that is selected by the main clause and a relative clause embedded in the nominal subordinate clause. 2.2 Subordination Subordination has been seen as an important developmental step making the transition from simple to complex sentences. Subordination is defined as a dependent clause within another sentence (Gillis and Schaerlaekens 2000) with the function of a noun, adverb or adjective in a resultant complex sentence. The initial phase of subordination is when children start to use preconjunctional subordinate clauses that lack the complementizer (Penner and Muller, 1992). From there they start to acquire the adult language system with the syntactic knowledge that requires the use of complementizers (Armon-Lotem, 2005). At the end of the critical period (Lenneberg et al., 1967) typically developing children have acquired all types of subordination, regardless of whether or not they are used correctly. Sometimes they still lack a complementizer or have main clause word order). Nippold in her studies (Nippold, et al. 2005 and Nippold, 2009) distinguishes three different (main) types of subordination (see table 3). Table 3 Three categories of the main subordinate clause types. Examples are complex clauses consisting of a main clause and a subordinate clause (placed between brackets) (Nippold et al., 2005, 2009). - adverbial clause: a phrase that functions as an adverb in a sentence. vb. The dog never barks, [when I pat him]. - nominal clauses: a subordinate clause that functions as an obligatory constituent of the main phrase. vb. - Marie knows [that her dog will not bark at acquaintances]. relative clause: a subordinate clause that modifies a noun phrase (most commonly a noun). vb. I once heard him bark to the postmen [who entered the yard]. 24 Earlier we concluded that simpler structures are acquired earlier than more complex structures. There is no doubt that these sentences (see table 3) are more complex than simple root clauses (see section 2.1) and they thus have to be acquired last. The order of acquisition of the different subordination types could provide information about the complexity of each individual type of subordinate clauses. Within the linguistic field there is some discussion about the order of acquisition of these different types of subordinate clauses for different languages, most likely due to cross-linguistic differences (Bowerman 1979; Bloom et al. 1980; Penner, 1995; Dromi and Berman 2008). As far as know for Dutch no data are at hand about the acquisition order of the different types of subordinate clauses. Although the expectation is that all adult subjects will have acquired all the syntactic structures, knowledge about the acquisition order could have been helpful to predict which type of subordinate clauses is last acquired and therefore will be most problematic (and therefore less produced, more erroneous or avoided) in hearingimpaired adults. What can be seen from the various subordinate structures is that the nominal subordinate clause forms a part of the main clause, and so is represented in the surface structure. It refers to one layer of embedding, as the sentence is selected by the verb phrase, and also embedded in the verb phrase (VP). The clause is a complement to a main clause and is in itself a noun phrase (NP) in the VP. The adverbial subordinate clause is different from the nominal subordinate clause. Adverbial subordinations are not required by a verb (form no argument of the predicate), but are an addition to the main clause, and they are therefore called nonselected. An adverbial clause is a single sentence in the main clause and also involves one layer of embedding. The relative clause is also a non-selected embedded clause, which on its own involves one layer of embedding. Based on their research Delage and Monjauze (2008) and Delage and Tuller (2009) considered this to be the most complex type of subordination due to: significantly lower mean number of relative clauses produced in mild-to-moderate hearing impaired compared to typically developing children and adolescents, and participants avoiding relative clauses by using a simple clause. 25 2.3 Measuring syntactic complexity This thesis will look at syntactic complexity from a language-based perspective (Nieminen, 2009). This means that the language itself is the starting point and that application of language and the language user are disregarded. This implies that statements on this form of syntactic complexity hold for both children and adults, typically or atypically developing, because it is independent of the language user. This absolute approach of linguistic complexity views complexity from an objective and linguistic theoretical perspective, as a measurable linguistic feature. Studies on syntactic growth and syntactic complexity show the use of different measures to measure language development and linguistic complexity in a-typically developing children, adolescents and adults (Hunt, 1970; Delage & Tuller, 2007; Hamann et al. 2007; Marinellie 2004; Nippold et al., 2005, 2007, 2008; Nieminen, 2009). The main measures used are Mean Length of Utterance or T-unit (counting length), and type and number of embeddings on the basis of which clausal density is measured (also called ‘subordination index’). These measures will be described in the following sections (2.3.1 and 2.3.2). 2.3.1 Mean Length of Utterance Mean Length of Utterance (MLU) is the first way of measuring language development and is often used to identify language impairment. MLU is based on the idea that “… almost every new kind of knowledge increases length: the number of semantic roles expressed in a sentence, the addition of obligatory morphemes, coding modulations of meaning, the addition of negative forms and auxiliaries used in interrogative and negative modalities, and of course, embedding and coordination” (Brown, 1973, p.53-54). MLU can be measured by counting the morphemes or words per utterance, communicative unit (C-unit), or terminable unit (T-unit) (Nippold, 2010). A T-unit is defined as an utterance that must contain one main clause and optionally may contain one or more subordinate clauses (Scott, 1988). The difference between Mean Length of T-unit and Mean Length of C-unit is that in the latter all communicative expressions are counted, also when they lack an independent clause (Loban, 1976) for example, the answer ‘‘no’’ to the question ‘‘Do you play basketball?’’ is counted as a C-unit). MLU calculations can vary in many ways and the results are not unambiguously cross-linguistically comparable (Nieminen, 2007). 26 The validity of the mean number of morphemes or words, per sentence or per shorter linguistic unit, as a measure of language development is supported and has been proved useful for analysing spontaneous speech in young children (Hunt, 1970; Loban, 1976; Bol and Kuiken, 1988). Research results show a slow but steady growth of MLU throughout childhood and adolescence into adulthood and show that MLU measures for atypically developing children are overall lower than for normal developing children. Mean length of T- (or C-) unit is considered to be an important marker of later syntactic complexity (Hunt,1970; Loban,1976; Nipoold, et al., 2005). As Nippold et al. (2005) suggest, the Mean Length of T-unit gives us information about the unit length, and combined with the amounts of different sentences types (coordinate clauses and subordinate clause types) can provide information about the ratio between sentence length and number of embedded clauses. This provides insights in complexity of sentences of language users. This would imply that it can reveal possible differences is the production of subordinate clauses between normal hearing and congenital hearing impaired adults. 2.3.2 Clausal densities As described above, a sentence can consist of several T-units, that each consist of an independent (main) clause and possibly contain one or more dependent, subordinate clauses. Besides Mean Length of T-unit some studies show that clausal density is another indicator of syntactic complexity (i.a. Nippold, 2005). The total number of T-unit combined with the amounts of different sentences types can provide information about the clausal density, an important marker of later syntactic development. Clausal density, also referred to as subordination index, is defined as ‘‘the average number of clauses (main and subordinate) per T-unit’’ (Scott, 1988, p. 58). It is measured by summing the total number of clauses (independent + subordinate), divided by the total number of T-units produced in a language sample. Clausal density, is the ratio of the number of (in)dependent sentences per T-unit produced. During language development children formulate sentences more efficiently, while making increasingly more use of subordinate clauses. This means that clausal density increases during language development. Clausal density has showed agerelated increases and therefore has proven to be a good indicator for growth of syntactic complexity (Nippold et al., 2005, 2008; Nippold, 2009). In atypically developing children it has been shown that they make us of simpler sentence structures longer and make less use of subordination (Delage and Tuller, 2009; 27 Tuller et al., 2012). This tendency also seems to continue in atypically developing adolescents (with mild-to-moderate hearing impairment or specific language impairment) and it would be a logical assumption to see the same in adults who have had an atypical language development. A person who produces little or no subordinate clauses, and thus syntactically less complex language than a person who produces many subordinate clauses, will have a lower clausal density. In several studies (Nippold et al., 2005, 2008; Nippold, 2009), in addition to the distinction between independent and dependent, a distinction also has been made between the different types of subordinate clauses. (The contents of this subordination classification and its implications for syntactic complexity have been discussed in sections 2.1 and 2.2.) For these sentences types separately a density can be calculated by summing the total number of main clauses + the specific type of subordinate clauses, divided by the total number of T-units. This results is a nominal clausal density (NCD), adverbial clausal density (ACD) or relative clausal density (RCD). Of all these clausal densities Nippold et al. (2005) stated that relative clausal density must be considered to be a better measure for syntactic complexity than clausal density, nominal clausal density and adverbial clausal density, because this variable is the most sensitive to growth (together with Mean Length of T-unit) and reveals more differences between normal hearing subjects of different ages (children, adolescents and young adults). Although the language of the subjects that participate in my study is mature, it is likely to find differences in the relative clause production between moderate-tosevere and normal hearing adults. Simple relative clauses are produced in children but much more by adults, who have access to the full range of relative clause types. Given their possibly delayed language development due to their congenital hearing impairment, it is quite possible that moderate-to-severe adults will experience problems in the production of subordinate, and specifically relative, clauses. The clausal densities within this research can provide information about syntactic complexity of moderate-to-severe adults compared to normal hearing adults who had a typical language development. 2.4 Research questions The preceding sections have shown the importance of optimal exposure and access to language input early in life. It has been argued that when a child cannot fully benefit from the language input from his environment during the critical period, it is at risk of language problems. These problems occur in different aspects of 28 language, but predominantly in the areas of phonology and (morpho-) syntax. Language does not normalize with age in people with mild-to-moderate hearing loss. (Delage and Tuller 2007). Previous research (Delage et al., 2008; Delage and Tuller 2007) has shown that hearing impaired children and adolescents show syntactically less complex language than normal hearing people. Subordination, and especially relative clause constructions, is considered to be the best indicators for the acquisition and growth of syntactic complexity in the spontaneous speech of typically and atypically developing children and adolescents. (Nippold et al. 2005; Nippold et al. 2008). Both these indicators showed an age related increase, meaning that younger children, when they become older, use more and more subordination and especially relative clauses. This increase continues into early adulthood (Nippold et al. 2005). Analyses of spontaneous speech samples showed behaviours of avoiding complexity by low production of complex structures, frequency of failed attempt and alternative strategies in hearing impaired children and adolescents (Delage et al., 2008; Delage and Tuller, 2009). Although several studies have investigated the syntactic complexity in typically and atypically developing children and adolescents, there are no studies known on the syntactic complexity in impaired adults, comparing them to normal hearing adults. Because the effects of hearing impairment on language acquisition and speech remain later in life, it is plausible that moderate-to-severe congenital hearing impaired (MSCHI) adults still encounter problems in reduced syntactic complexity, avoidance strategies or more erroneous (complex) sentences (Delage et al., 2008). The aim of this thesis is thus to investigate the syntactic complexity, measured by subordinated and specifically relative clause production, errors related to embedding occurring subordinate clauses, and possible avoidance patterns and compensatory strategies in congenital hearing impaired Dutch adults. The studies by Nippold et al. (2005, 2008, 2009) and Delage et al. (2007, 2008) as described in the previous sections will serve as a theoretical framework for my empirical research. Based on these researches the following research questions will be addressed in this thesis: Research questions: 1. Do adults with a congenital, moderate to severe hearing impairment produce less complex language than adults with normal hearing? a. Do adults with a congenital, moderate-to-severe hearing impaired produce shorter utterances than adults with normal hearing? 29 b. Do adults with a congenital, moderate-to-severe hearing impaired have a lower clausal density than adults with normal hearing? c. Do adults with a congenital, moderate-to-severe hearing impaired have a lower relative clausal density than adults with normal hearing? d. Do adults with a congenital, moderate-to-severe hearing impaired have a lower nominal clausal density than adults with normal hearing? e. Do adults with a congenital, moderate-to-severe hearing impaired have a lower adverbial clausal density than adults with normal hearing? 2. Do adults with a congenital, moderate-to-severe hearing impairment make more errors than adults with normal hearing? 3. Do adults with a congenital, moderate to severe hearing impairment use avoidance strategies more than adults with normal hearing? I will propose the following hypotheses about the syntactic complexity in moderate-to-severe hearing impaired adults. Hypotheses: 1) Normal hearing adults will produce more syntactically complex language than hearing impaired adults and therefore have a higher clausal density and relative clausal density. 2) Clausal density of normal hearing adults to be higher than the density of moderate-to-severe hearing impaired adults. 3) Relative clausal density will be higher than clausal density and provide a better distinction between normal hearing adults compared to moderate-to-severe hearing impaired adults, and will therefore be a better measure for syntactic complexity than clausal density. 4) The spontaneous speech of moderate-to-severe hearing impaired adults will reveal avoidance patterns, to avoid syntactically complex structures. Avoidance of syntactic complexity will be higher in moderate-to-severe hearing impaired adults than in normal hearing controls and will affect the most complex structures. 30 5) Moderate-to-severe hearing impaired adults will make more morpho-syntactic errors in syntactically complex structures than normal hearing controls. 2.5 Summary and discussion In the preceding sections a theoretical and operational approach of syntactic complexity have been presented. Language development and syntactic growth are related to syntactic complexity, because growth in complexity is perceived as an index of development in linguistic abilities (Nieminen, 2009). This implicates that order of acquisition might be identical to the order of complexity. Syntactic constructions that emerge later in typical language development and also emerge more slowly and/or cause problems in mild-to-moderate hearing impaired children and adolescents can be characterized by a degree of higher computational complexity (Nippold et al., 2007; Hamann et al., 2007). Syntactic complexity especially seems a sensitive indicator for (persistent) language problems. Subordinate clauses are the last syntactic structures to be acquired and considered to be the most complex syntactic structures, in which persistent language problems remain visible. Syntactic complexity is operationally determined by the increasing production of the Mean Length of T-unit, clausal density, and subordinate clausal densities (nominal clauses, adverbial clauses, and relative clauses) (Nippold et al., 2005; Nippold et al., 2007; Nippold et al., 2008). Mean length of T-unit and relative clausal density are considered to be the best measures for syntactic complexity (Nippold et al., 2005). Based on these data research questions and hypotheses are formulated on the syntactic complexity of moderate-to-severe hearing Dutch speaking adults. These will form the core of the research presented in the following chapters (chapter 3 and 4). 31 3 Method 3.1 Participants For the project (pilot-study) of Elke Huysmans and this research Elke and I agreed on using the same test group. Together we recruited normal hearing adults (N=10) via an advertisement via e-mail, which was distributed to our friends and acquaintances. Moderate-to-severe hearing impaired adults (N=20) were all patients in the VU medical centre, KNO-audiology, they were approached for voluntary participation in the study. The VU Medical Centre medical ethics approved the study. When investigating the syntactic complexity of congenital hearing impaired adults, it is important to study the language of subjects with a minimum age of 20 years and a maximum age of 40 years. Studies show that at the age of 20, language proficiency in the normal population is well established. Nippold et al. (2005) studied the syntactic complexity of the spontaneous language of normal hearing people with different ages (7-49 years) and concluded that syntax continues to develop beyond adolescence and into early adulthood (20-29 years), but remains stable in middle age (40-49 years). There is no evidence for continued growth beyond early adulthood. Therefore, the minimum age of the subjects was set at 20 years. The age of the subjects was limited at 40 years to prevent the interference of deteriorating auditory functions as a result of age (presbyacusis). For all normal hearing participants hearing was tested calculating the pure-tone average (PTA), using an exclusion criterion of a pure tone average of 20 dB on the best ear (see section 1.1 for Fletcher Index; average number of decibels by 500, 1000, 2000 Hz). For some moderate-to-severe congenital hearing impaired subjects a recent audiogram was filed in their medical record, for others a new audiogram was made, handling a pure tone average of 35 dB on the best ear. Based on a combination of anamnestic questionnaire and audiometric data it was clear that all congenital hearing impaired adults were hard of hearing (35 to 95 dB HL) from birth. People with additional problems such as a diagnosed cognitive delay (IQ<80), specific language impairment or psychiatric disorder (e.g. ADHD) were excluded. For an overview of the characteristics (FlI, hearing rehabilitation and education) of the participants see table 4. 32 Table 4 Overview of the characteristics of the normal hearing and moderate-to-severe NH01 NH02 NH03 NH04 NH05 NH06 NH07 NH08 NH09 NH10 HI 01 HI 02 HI 03 HI 04 HI 05 HI 06 HI 07 HI 08 HI 09 HI 10 HI 11 HI 12 HI 13 HI 14 HI 15 HI 16 HI 17 HI 18 HI 19 HI 20 20 24 21 22 24 34 26 34 24 20 33 34 27 31 21 32 20 20 24 25 39 34 23 30 29 45 23 20 24 28 18 2 2 8 18 2 3 5 5 3 58 93 88 50 50 83 35 90 68 52 108 78 50 102 88 107 57 95 102 83 n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. no no no no no yes no yes no no yes no no yes no yes no yes yes yes n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. n.a. HA CI HA HA HA HA HA HA HA HA CI HA HA HA HA CI HA CI HA HA H H H M M M M L M L H H H H M H L H H H M H H H M L M L M M Special e secondary education Special primary education level of education current type of hearing rehabilitation Progressive hearing loss current PTA 500-1000-2000 best ear age subject congenital hearing impaired subjects participating in this study. + + + + + + + + + + + + + + + + - All participants had Dutch language as their mother tongue, were monolingual (some moderate-to-severe hearing impaired adults had had special education for hearing impaired, but had not been exposed to a sign language) and were at least VMBO-T educated (Lower General Secondary Education/ UK GCSE's at C level). The 33 overall educational level of the participants in this study was matched with the distributions of the general education levels of the Dutch population; meaning all levels of education were represented (low (L), middle (M) and high (H)) with more middle and low educated participants than highly educated. The attempt was to form two groups (normal hearing and moderate-to-severe hearing impaired) that were equal for educational level. For the normal hearing group the distribution of educational level is L=20%, M = 50% and H=30%. For the moderate-to-severe hearing impaired group the distribution of educational level was L = 15% M=30% and H=55%. Unfortunately Elke Huysmans and I did not fully succeed, ending with the hearing impaired group being slightly higher educated than the normal hearing group. 3.2 Data collection All participants were subjected to a test battery, consisting of an interview eliciting a spontaneous speech sample (to obtain data for both Elke Huysmans (Huysmans et al., to appear) and my own project), the CELF-4 NL test (Clinical Evaluation of Language Fundamentals, Semel et al., 2008) (to provide (not standardized) data about the subjects overall language abilities for the project of Elke Huysmans) and a writing task (for follow-up research within the project of Elke Huysmans on writing skills in hearing impaired adults (Groenestyn, 2011). The testing procedure and results on the latter two tests/ observation instruments are not included within the research presented here. For examining the syntactic complexity within this thesis I decided only to examine and analyze the spontaneous speech samples, expecting that these would provide the most complete view of the language ability and syntactic complexity of the subjects. To measure syntactic complexity it is necessary to elicit language from subjects that is suitable for analyses. Spontaneous speech samples were elicited by interviewing the participants about their favourite game or sport. Nippold (2005) showed that this task is a good way to trigger expository discourse. Expository discourse is the use of language to convey information in the form of a monologue (Bliss, 2002). This discourse genre has proven to be more effective for eliciting complex syntax in typically and atypically developing people than narrative or conversational discourse. Verhoeven et al. (2002) found that in Dutch, English, French, Hebrew, and Spanish grade-school children and adults all kinds of subordinate clauses occurred more often in expository discourse than in narrative texts. Nippold 34 (2005) found that the language of children as well as of adolescents and adults was more complex in expository discourse than in conversational discourse. Especially relative clause production was very sensitive to discourse type; adults showed this type of subordination more often in expository discourse than children. Based on these results within this project the method of Nippolds ‘favourite game or sport task’ (2005) exactly was used to obtain our language samples. The questions posed to the subjects are shown in table 5. Table 5: Questions eliciting expository discourse in the ‘favourite game or sport task’ (FGST) (Nippold, 2005, p.152) A. "What is your favourite game or sport? B. "Why is [x] your favourite sport?" C. "I’m not so familiar with the game of [x], so I would like you to tell me all about it. For example tell me what the goals are, how many people play the game. Also tell me about the rules that players need to follow. Tell me everything you can think of about the game of [x] want you to assume that I know nothing about (x), so that someone who has never played before will know how to play. D. Now I would like you to tell me what a player should do in order to win the game of [x]. In other words, what are some key strategies that every good player should know? All interviews were conducted by the same two researchers, strictly following the questionnaire to prevent differences in questioning, and were audio taped for later transcription. The first two questions (A and B) were asked to introduce the topic of the conversation and make the person feel at ease; they elicit conversational discourse. Questions C & D were asked to elicit an expository discourse and to elicit complex language use. For this purpose we asked our subjects to describe a competitive sport, whereby they had to explain the rules of the game carefully so that the investigator would understand. There was no time limit, but participants were challenged to tell as much as possible about their chosen sport. Spontaneous speech that was elicited by these last two questions (C and D) was used for analysis. 35 3.3 Analysis All language samples were transcribed using the principles for sentence segmentation of the STAP procedure (van den Dungen and Verbeek 1999). For analysis, only free expressions (= all sentences that are no answers to question, consisting of a single main clause, and (optionally) one or more subordinate sentences) were taken into account, because they contain by the subject selfformulated sentences. Elliptical utterances (= answers referring to an (indirect) question, and often an elliptical sentence) were left out of the analysis, even as nonfluent speech: false starts, incomplete sentences, and (word) phrase repetitions (STAP-procedure, van den Dungen and Verbeek 1999, p. 13-17). Samples were analyzed for T-units (see section 2.3.1). Marinellie (2004) found that a sample of 100 utterances (in conversational discourse) yields a reliable and representative sample, yielding examples of all complex sentence structure of interest (compound, nominal, adverbial and relative clauses, for examples see section 2.1 and 2.2 (table 3). The aim of this study was to collect a language sample of at least 50 T-units spontaneous speech in expository discourse per subject. The expectation was that a minimum of 50 utterances in expository discourse would yield a representative sample comparable with 100 utterances in conversational discourse. Although in many cases the ‘favourite game or sport task’ resulted in an expanded speech sample, some subjects produced fewer than 50 T-units. There was a large variation in sample sizes, ranging from 23 to 211 T-units (normal hearing 47-76; moderate-to-severe hearing impaired 23-211). This brought a dilemma about whether or not excluding the smallest samples within the limited test group. Even the norm of 40 T-units would have meant exclusion of 5 subjects. All T-units were analyzed for presence of compound clauses and subordinate clauses, subcategorized by nominal, adverbial and relative subordinate clauses (following the procedures of Hunt, 1970 and Nippold, 2005). Some small samples contained all types of complex sentences (for example CHI produced 26 T-units containing all types of complex syntactic structures), while in larger samples this was not the case (NH1 produced 76 T-units, with no relative clause). Nevertheless, all participants produced at least 3 out of 4 complex sentence structures. This implies that the smaller samples need not be of less value and should not be inferior to larger samples when it comes to complexity. Given this, it was decided to include all subjects analyzing the samples to a maximum of 100 T-units. Because not all samples contained the same number of t-units and length of the speech sample 36 differed too, all primary data are calculated into averages and percentages to be able to compare all group outcomes (see table 6). Table 6 The averages and percentages of the primary data (total number of T-units, compound clauses and subordinate (subdivided into nominal, adverbial and relative clauses) of normal hearing and hearing impaired adults. NH Total T- (N=10) unit % % %rel cl % adv cl % Nom Compound Subordinate clause cl clause Mean 62,5000 31,0000 23,1000 17,2920 49,9040 32,8050 Median 61,0000 26,5000 23,0000 20,8350 49,7750 36,3950 11,05793 13,10640 8,19824 13,52910 17,06921 8,28438 % adv % Nom cl cl Std. Deviation MSCHI Total T- % % (N=20) unit Compound Subordinate clause clause %rel cl Mean 72,9500 29,9500 21,0500 18,5145 48,5252 32,9605 Median 58,5000 30,0000 18,0000 17,2650 50,2600 29,2750 53,16655 14,46038 8,75680 13,6379 22,0486 17,4893 7 3 5 Std. Deviation 3.3.1 Syntactic complexity As described in section 2.3.1 and 2.3.2, there are several important measures for measuring syntactic complexity: Mean Length of T-unit, clausal density and subordinate clausal densities. These measurements were used in this study to reveal difference in syntactic complexity between moderate-to-severe hearing impaired and normal hearing adults. Below a brief explanation of these measures and the calculation methods will be presented. A. Mean length of T-unit (MLU) In order to be able to answer research question 1.a (see section 2.4), if congenital, hearing impaired adults produce shorter sentences than normal hearing 37 peers, the Mean Length of T-unit (see section 2.3.1) was calculated (Hunt, 1970). This was done using the following calculation: Total number of communicative words : total number of T-units = Mean Length of T-unit B. Clausal density (CD) or, subordination index In order to be able to answer research question 1.b (see section 2.4), if clausal density is lower in moderate-to-severe hearing impaired adults than normal hearing adults, the clausal density (see section 2.3.2) was measured. This is a measure of syntactic complexity that produces a ratio of the total number of clauses to the total number of T‐units, resulting in the average number of clauses, main and subordinate, per T-unit (Scott, 1988, p. 58). Clausal density was measured by using the following calculation: total number of main clauses + total number of subordinate clause (NOM+ADV+REL) : total number of T-units = clausal density C. Subordinate clausal densities In order to be able to answer research questions 1.c, d and e, if the different subordinate clausal densities are lower in moderate-to-severe hearing impaired adults than normal hearing adults, the clausal densities (see section 2.3.2) for every subordination type were calculated separately. This was done using the following calculation: total number of main clauses + total number of dependent clauses of a specific subordination type (nominal adverbial or relative): total number of T-units = subordinate clausal density Depending on the type of subordination used in the calculation, you can measure nominal clausal density (NCD), adverbial clausal density (ACD) and relative clausal density (RCD). Comparison of these densities would constitute evidence for the hypothesis 2 (see section 2.4), that relative clausal density shows greater differences between normal hearing and hearing impaired adults and therefore a better measure than the other densities (clausal, nominal and adverbial). 38 3.3.2 Errors Studies on complexity in mild-to-moderate hearing impaired (Delage et al., 2008; Delage and Tuller, 2009) and specific language impaired subject (Marinellie, 2004; Tuller, 2012) show that atypically developing children and adolescents make more errors than normal hearing pears. Errors occur mainly in the most complex sentences types. In existing studies on syntactic complexity in atypically developing subjects examples of errors are presented, but the different types of errors are not clearly classified. To provide an answer to research question 2, if moderate-to-severe hearing impaired adults make more errors than normal hearing adults, all subordinate clauses were analyzed for errors. Only subordinate clauses were analyzed, and not main clauses, because these clauses are considered to be the most complex structures, and therefore most susceptible to errors. Because errors categories based on literature were not available, it was decided to create ad hoc categories, based on the different types of errors that occurred in the analyzed subordinate clauses. Standard Dutch language was used as a starting point to test the grammaticality of all subordinate clauses. Language forms and constructions that differed from the standard Dutch, even if these errors within a regional dialect possibly could be considered as correct language, were reviewed as errors. Errors were categorized in errors inside and outside the subordinate clause structure. Word order errors (embedded V2) and errors in, or omission of demonstrative pronouns and complementizers that directly influenced the subordinate clause structure were considered to be errors inside the subordinate clause structure. All other errors were classified as errors outside the subordinate clause structure. The different error categories, with corresponding examples are listed below. 1) Wrong relative pronoun: *het doel [dat is een rechthoek [wat the goal that is a rectangle what rechtop staat]] upright stands met een net erin with a net in.it “The goal is a rectangle that stands upright with a net in it.” 39 2) pronoun deletion: *Dus als ‘t iemand So if van je eigen team is ø [de bal uitschopt], dan … it someone from your own team is ø the ball kicks , then "So if it is someone from your own team who kicks the ball, then …” 3) wrong complementizer: *als het zijn fout If it his is, ødoor de bal in de eigen veld terugkomt fault is, ø.by the ball in the own ,dan… field comes.back ,then… “If it is his fault, causing the ball to fall back into the own field, then…” 4) complementizer deletion: *maar [ø bijvoorbeeld de tussenstand But nog vijf vijf is] … ø for.example the intermediate.position still five five is … "But for example when the intermediate position is still five five ...” 5) embedded verb second (V2) clauses Embedded verb second clauses (V2) are embedded clauses (nominal and adverbial) with main clause word order (the verb in second position). A negative element in the main clause makes the embedded V2 impossible. Embedded V2 clauses can only be preceded by the complement omdat ‘because’ if the given reason in the embedded clause is an established fact (Zwart, 2011, p. 123/ 124). *maar waar but het om gaat is wie is de where it snelste na die twintig ritten to goes is who is the fastest after this twenty tours “But what matters is who is the fastest after twenty tours” All other ‘outside subordinate clauseerrors made by the subjects that could not be grouped into any of the categories described above (e.g. errors in verb conjugations, plurals, omissions of articles) were classified as errors outside the subordinate clause structure. These errors, within this research, were not further specified (for a complete analysis off all the morpho-syntactic errors made by the 40 normal hearing and hearing impaired adults in the same spontaneous speech samples see Huysmans et al., to appear). 3.3.3 Avoidance of syntactic complexity and compensatory strategies In order to answer the third research question, if moderate-to-severe hearing impaired adults use more avoidance and compensatory strategies than normal hearing adults, the spontaneous language samples for both groups were analyzed for avoidance and compensatory strategies. The researcher examined the sentences in which a subordinate clause structure could have been used, but where another type of sentence construction was used instead of subordination. In section 1.2.2 different avoidance strategies (e.g. direct speech, juxtaposition) have been described that have been discussed in the literature. It was noted that the term avoidance is not entirely uncontroversial, and some categories are ambiguous. Based on literature and examples from the samples unambiguous categories of avoidance were formed. Sentences constructions that did not fall within these categories, such as ambiguous sentences (due to complex mixing constructions where the meaning of the sentence was not clear) are excluded for analysis on avoidance. 1 ) Direct speech: Direct speech is a representation of words or an expression of a person in the form of a quotation (Vandeweghe, 2004 p.280). Instead of direct speech a nominal subordinate clause could have been used. Compare the examples 1 and 2, where 1 represents direct speech and 2 a main clause with nominal subordinate clause: 1. You can say: “I want it faster”. 2. You can say [that you want it faster]. Compared to a subordinate clause, direct speech lacks a complementizer and has V2 word order (instead of the subordinate word order where the verb occurs at the end of the sentence), and thus is considered to be less complex. Use of direct speech could therefore be a strategy used by hearing impaired adults to avoid complexity. 41 2) Verb first subordinate clauses Verb first (V1) constructions are subordinate constructions where the first constituent is not a subject, but the first place in the sentence is filled with a finite verb. This type of subordination was only found in conditional clauses with an adverbial if … then-constructions. In Dutch subordinate clauses the final verb occurs in final position. In Verb 1 subordinate clauses the verb precedes the subject, occurring in sentence initial position, the position that in a normal subordinate clause would be filled with a complementizer or relative pronoun. In Verb 1 subordinate clauses the complementizer if is omitted. Compare example a, a sentence with verb 1 construction, with sentence b, where the same sentence (with same meaning) with normal subordinate word order is presented. staat het paard scheef dan krijg je does the horse lean than get minder punten you less points “does the horse lean, then you get less points” This sentence type is considered to be less complex, because of the missing subordinate word order and the absence of a complementizer. 3) Clausal conjunction Clausal conjunctions are sentences that resemble a relative clause construction, but have the verb in second position (V2). Other than verb second constructions in nominal and adverbial (see the description of the error categories in this section), clausal conjunction in relative clauses does not (necessarily) lead to an ungrammatical sentence. Instead of a main clause with a subordinated relative clause it results in two simple main clauses in juxtaposition. The relative pronoun loses its function of initiator of the subordinate clause, but has the function of a demonstrative pronoun. Compare the following two sentences where 1 represents an example of a relative clause construction and 2 shows an example of clausal conjunction: 1) dat is een mannetje [die dan that is a guy buiten die teams staat] who then outside these teams stands “that is the guy who then stands outside these teams” 42 2) dat is een mannetje, die that is a guy, staat dan buiten die teams” who stands then outside these teams “that is the guy who then stands outside these teams” In the last sentence the word die is not a relative pronoun but a demonstrative. Compare sentences 3 and 4: 3) dat is een mannetje waar that is a man.little where iedereen bij wil horen everyone to wants join “That is a little man who everybody wants to join” 4) dat is een mannetje (en) daar wil that is a man iedereen bij horen (and) there wants everyone to join “That is a little man everybody wants to join” The noun phrase specified by the specifying coordinated clause must be non-specific (unlike the relative construction). Also the first part of the sentence cannot be a question, command, or contain a negation or an intentional verb. No such restrictions apply to regular relative constructions (Zwart, 2011, p.126). 4. Results In this chapter the results from the analyzed data of the spontaneous language of moderate-to-severe congenital hearing-impaired and normal hearing adults will be discussed. First, a ‘test for normality’ (Kolmogorov- Smirnov) was done for all variables to see if the data were normally distributed. All important variables were not normally distributed, as a logarithmic test also showed. The Mann Witney-U test, a non-parametric tests for independent samples, was therefore used for statistical analysis. As discussed in section 3.3 the samples varied considerably in number of utterances. For the normal hearing group this range was between 47-76, with a median of 61.0 utterances. For the hearing impaired group the range was between 23-211 utterances, with a median of 58.5 utterances. There was no significant difference in group size between the hearing impaired and normal hearing adults [Mann-Whitney U = 81,000; NH = 10, MSCHI = 20, P> 0.05]. 43 The results that will be discussed in the following sections, 4.1 to 4.3, will show whether there are differences between the both groups on syntactical complexity, error rates and avoidance strategies and if and how these results on statistical analysis provide answers to the research question as formulated in section 2.4. For both groups all variables and data are reported in appendix III. 4.1 Results for syntactic complexity Syntactic complexity was measured by 6 variables: mean length of utterance (MLU), mean length of the 5 longest utterances (MLUL), clausal density, nominal clausal density, adverbial clausal density and relative clausal density. Results on these variables are presented in table 7 (for normal hearing adults) and in table 8 (for moderate-to-severe hearing impaired adults). The results of moderate-to-severe congenital hearing impaired and normal hearing adults on MLU and the MLUL were compared. There were no significant differences in performance between the two groups on these measures. [MannWhitney U = 88.000 for MLU and 87.500 for MLUL; NH= 10, MSCHI= 20; p>0.05]. Although for Dutch no data are available regarding Mean Length of the (longest) Uterrance(s) in adults, the results found in this research were similar to those found by Nippold (2005, table 1, p.1053) for English, normal hearing adults. Research question 1.a is thus answered: adults with congenital moderate-to-severe hearing loss do not produce shorter sentences than normal hearing impaired. Table 7. Descriptive statistics on measures of language production for expository discourse for normal hearing adults. NH ML T-unit MLU5L (N=10) Clausal Relative Adverbial Nominal Density CD CD CD (CD) Mean 10,0250 25,6800 1,3690 1,0750 1,1740 1,1210 Median 10,1150 25,2000 1,3900 1,0750 1,1600 1,1300 1,30343 5,32933 ,11318 ,06721 ,05739 ,05087 Std. Deviation 44 Table 8. Descriptive statistics on measures of language production for expository discourse for moderate-to-severe hearing impaired adults MSCHI ML T-unit MLU5L (N=20) Clausal Relative Adverbial Nominal Density CD CD CD (CD) Mean 10,3185 23,6600 1,3910 1,0725 1,1840 1,1350 Median 10,2450 23,0000 1,3900 1,0600 1,1400 1,1000 1,63059 3,87548 ,16638 ,06988 ,11417 ,11335 7,07 16,40 ,62 ,30 ,44 ,40 Std. Deviation Range For all complexity variables the Mann-Whitney U test was used assessing whether or not the samples from normal hearing and moderate-to-severe hearing impaired adults had different values on the most important variables for syntactic complexity. Overall the expectation was that moderate-to-severe adults would use syntactically less complex language and therefore would produce less of all types of complex clauses. Their scores on all complexity variables were expected to be lower compared the adults with normal hearing. Because the hypotheses (see section 2.4) were directional and obviously had one expectation it was suitable to look at the ttest only one-tailed. The data in table 9 show that on none of the complexity variables a significant difference was found [Mann Whitney U = range 83,500 to 98,500; NH=10, MSCHI=20; p<0.05] between the performance of normal hearing and moderate-to-severe congenital hearing impaired adults. Table 9 Results on the Mann Witney U test for complexity variables for normal hearing and moderate-to-severe hearing impaired adults. MannWhitney U Z Exact Sig. (2-tailed) Sig. (1-tailed) %nom %adv %rel % Clausal Relative Adverbi Nominal cl cl cl Direct density CD alCD CD speech (CD) 91,500 98,500 96,500 90,000 94,500 97,500 89,000 83,500 -,374 -,066 -,154 -,451 -,242 -,110 -,485 -,728 ,721 ,957 ,888 ,665 ,820 ,922 ,641 ,480 ,361 ,478 ,444 ,334 ,410 ,461 ,320 ,240 45 The density variables for syntactic complexity showed no significant differences between the two groups. These findings provide answers to research questions 1.a to e. Moderate-to-severe congenital hearing impaired adults do not have lower clausal densities than adults with normal hearing. Because differences in clausal density variables for both groups are not significantly different, it can be concluded that relative clausal density is not a significantly better measure for complexity than clausal density. 4.2 Results for error analysis The results for subordinate sentence grammaticality (analyzed for morphosyntactic error inside and outside the subordinate structure of the sentence, see section 3.3.2) are presented in this section. Table 10 shows the measures for subordinate clause grammaticality for adults with normal hearing, where table 11 shows the results for moderate-to-severe hearing impaired adults. Table 10 Results for subordinate clause grammaticality for adults with normal hearing. NH (N=10) % Ungrammatical % Error outside % Error inside subordinate clause subordinate clause subordinate clause structure structure Mean 4,1014 1,6071 2,4943 Median 1,6667 ,0000 ,0000 7,62412 3,98854 4,05026 Std. Deviation NH (N=10) % Wrong % % Wrong % pronoun Pronoun complementizer Complementizer deletion deletion Mean ,3846 2,5507 ,0000 1,2500 ,0000 Median ,0000 ,0000 ,0000 ,0000 ,0000 1,21626 4,75777 ,00000 3,95285 ,00000 Std. Deviation % V2 46 Table 11 Results for subordinate clause grammaticality for moderate-to-severe congenital hearing impaired adults. MSCHI (N=20) % Ungrammatical % Error outside % Error inside subordinate clause subordinate clause subordinate clause structure structure Mean 15,2043 13,7511 5,0038 Median 11,6516 7,7381 3,3482 15,42249 19,37362 6,20377 Std. Deviation MSCHI (N=20) % Wrong % % Wrong % pronoun Pronoun complementizer Complementizer deletion Mean deletion 1,2319 ,6401 1,3298 ,1282 1,6738 ,0000 ,0000 ,0000 ,0000 ,0000 2,45710 1,71033 2,79171 ,57335 2,74402 Median Std. Deviation % V2 Table 10 directly shows no results on wrong complementizer and V2, meaning that normal hearing adults made no errors in these categories. Hearing impaired adults made mistakes in all five error categories. To see if there were significant differences in the grammaticality of the produced subordinated clause, statistical analysis on the morpho-syntactic errors was performed. Results (see table 12) show that there is a significant difference in the amount of ungrammatical subordinate sentences. Hearing impaired adults produced more ungrammatical subordinate clauses than the normal hearing control group [Mann Whitney U = 85,500 N1=10 N2=20; p>0.05]. It should be noted that this involves all sorts of errors both inside and outside the clause structure. Isolated, the variable ‘errors outside the subordinate clause structure’ does also show a significant difference [Mann Whitney U = 55,000, P<0,05], where the category ‘errors inside the subordinate clause structure’ does not show a significant difference [Mann Whitney U = 75,000, p>0.05]. Based on these findings it can be concluded that hearing impaired adults do make more errors in complex clause structures than normal hearing adults. This answers research question 2 and provides evidence to accept hypothesis 4. 47 Table 12 Results on the Mann Witney U test for subordinate clause grammaticality and morpho-syntactic errors for normal hearing and moderate-to-severe hearing impaired adults. % Ungrammatical % Error outside subordinate clause % Error inside subordinate clause subordinate clause structure structure Mann-Whitney U 40,000 55,000 75,000 Wilcoxon W 95,000 110,000 130,000 Z -2,666 -2,149 -1,160 Exact Sig. (2-tailed) ,006 ,031 ,256 Exact Sig. (1-tailed) ,003 ,014 ,128 % % % Wrong % Wrong Pronoun complemen- Complementizer pronoun deletion tizer deletion Mann-Whitney U % V2 85,500 85,000 92,000 95,000 87,000 140,500 140,000 147,000 150,000 142,000 -,913 -1,267 -,542 -,707 -,735 Exact Sig. (2-tailed) ,465 ,458 ,640 1,000 ,445 ExacSig. (1-tailed) ,239 ,281 ,449 ,667 ,218 Wilcoxon W Z 4.3 Results for avoidance strategies Analysis of unambiguous avoidance strategies (see section, 3.3.3) only led to one category where numbers were large enough for statistical analysis. Both hearing impaired and normal hearing produced direct speeches. Although the average rate was slightly higher for hearing impaired adults (see table 13), a Man Whitney U test showed no significant difference between both groups (see table 14). Table 13 Results for direct speech for adults with hearing impaired adults and adults w normal hearing MSCHI (N=20) % Direct speech NH (N=10) % Direct speech Mean 2,4870 Mean 3,2700 Median 1,8850 Median 2,9850 Std. Deviation Std. Deviation 2,77277 3,63128 48 Table 14 Results on the Mann Witney U test for direct speech for normal hearing and moderate-to-severe hearing impaired adults. % direct speech Mann-Whitney U 110,000 Z -0,42 Exact Sig. (2-tailed) ,3372 Exact Sig. (1-tailed) ,06745 Some examples of verb first were observed in spontaneous speech samples of moderate-to-severe hearing impaired adults (occurring in 3 out of 10 samples) as well as in normal hearing adults (4 out of 20 sample). As said, number were small, except for a peak at one of the hearing impaired adults who produced 7 verb first sentences on a total number of 72 T-unit. Clausal conjunction was only observed in one sample of a hearing impaired adult. From this can be concluded that hearing impaired adults do not make (more) use of avoidance strategies than normal hearing adults. This forms the answer to research question 3. 5. Conclusion and discussion The aim of the research, executed in this thesis, was to provide answers to the research questions and hypotheses as formulated in section 2.4, which were formed based on the literature study in chapters 1 and 2. Answers were found by analyzing the spontaneous speech samples of 20 moderate-to-severe congenital hearing impaired adults and 10 normal hearing adults, that were obtained by eliciting expository discourse. No significant differences in appearance of complex clause structures in spontaneous speech sample between moderate-to-severe hearing impaired and normal hearing adults were observed. The language of all participating subjects, normal hearing and hearing impaired) comparable with the findings of Nippold (2005 and 2007 for normal hearing adolescents and adults), is characterized by complex syntax, using all syntactic structures and the ability to combine structures into longer sentences and (multi-) subordinate clauses. Moderate-to-severe congenital hearing impaired adults produced comparable amounts of nominal, adverbial and relative clauses, so that no difference in clausal densities was observed between both groups. This indicates that the language of moderate-to-severe hearing impaired adults is 49 not less syntactically complex than the language of the normal hearing adults. Hypotheses 1 and 2 on the basis of these findings must be rejected. A possible explanation for the equal performance on syntactic complexity could be that Dutch hearing impaired adults do not or no longer experience problems on syntactic complexity. Another plausible explanation could be the fact that the moderate-to-severe congenital hearing impaired were on average higher educated than the normal hearing controls. Higher education could indicate that the moderate-to-severe congenital hearing impaired group had a higher intelligence which could implicate that they have a more sophisticated ability to create complex language, including higher causal densities. The relation between intelligence and syntactic complexity in (normal hearing) adults could be a potential topic for further research. The small group sizes could also be a possible explanation, making statistical data less representative. The same counts for the sample sizes. In addition, the samples varied widely in size; some subjects producing less than 30 utterances. Although almost all types of complex sentences occurred in all samples, the small sample sizes could have negatively affected the statistical results. It would be interesting to do a similar study with a larger test group and by setting a minimum of 100 T-units (Marinellie, 2004) as an exclusion criterion. Regardless of the methodological aspects of the research another explanation for the observed findings could be found in the linguistic proficiency of the subjects as a result of a completed maturation. Clausal density and especially relative clause production are two indicators for syntactic complexity that are sensitive to growth (Nippold (2005, 2009). Because of the language being fully mature for adult subjects there may be no difference in use of complex sentences between moderate-tosevere hearing impaired and normal hearing adults. The would argue for normalisation of language in the moderate-to-severe hearing impaired subjects participating in this study, which is contrary to the findings of Delage and Tuller (2007). However, that language does not normalize with age can be demonstrated by the significant difference for number of errors made in subordinate clauses between moderate-to-severe hearing impaired and normal hearing adults; all types of ‘errors inside the subordinate clause structure’, merged as one variable, and the variable ‘errors outside the subordinate clause structure’ together demonstrated a significantly different between both groups. Moderate-to-severe hearing impaired adults do make more errors in complex syntax than their normal hearing peers, 50 which supports hypothesis 4. ‘Errors outside the subordinate clause structure’ within this thesis are not further specified in this research, but a quick look at the data does show that errors do occur in the unstressed morphemes, components likely to be missed by hearing impaired children acquiring language. The most common mistakes are made in verb inflections (for example hij komø / ‘he comeø’) and using the wrong determiner or omitting a determiner (gedurende ø hele wedstrijd / during ø whole game). These results are similar to those of Elfenbein (1994). The findings suggest that language of the subjects participating in study in the participating did not normalize with age as they still have problems with morpho-syntax / grammar. To provide an answer to the question if more errors do occur in syntactically complex sentences (subordinate clauses) than in syntactically less complex sentences (as simple main clauses and coordinate clauses) it is necessary to know how many ungrammatical (categorized) main clauses were produced by the subjects. These data for this study were unfortunately not (yet) available, but will be published soon (Huysmans, et al. to appear). In the future it would be very valuable to combine the research results of these studies. This could possibly lead to new insights on the relation between morpho-syntactic errors and syntactic complexity. The compensatory strategies that moderate-to-severe hearing impaired adults would possibly use in their spontaneous speech formed a complicated category within thesis. Compensatory strategies have not been extensively studied nor clearly described. In this thesis it was tried to form some unambiguous categories of avoidance strategies. It was hypothesized that moderate-to-severe hearing impaired adults would use more avoidance strategies than normal hearing adults. This does not seem to be the case. Although the amounts of examples per avoidance variable were too small for statistical analysis, all kinds of avoidance patterns (e.g. direct speech, verb first) were observed in moderate-to-severe hearing impaired adults and less or not in normal hearing adults. 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Le langage et 'homme: logopédie, psychologie, audiologie 14, 191-207 Tuller, L. , Herny, C. Sizaret, E. and M. Barthez (2012) Specific language impairment at adolescents: avoiding complexity. Applied Psycholinguistics 33, 161-184 Vandeweghe, W. van (2004) Grammar of the Dutch phrase Antwerpen/ Apeldoorn: Grarant Uitgevers n.v. 57 Verhoeven, L., M. Aparici, D. et al. (2002) Clause packaging in writing and speech: A cross-linguistic developmental analysis. Written Language & Literacy 5, 13561 Zwart, J. (2011) The syntax of Dutch. Cambridge: Cambridge Univerisity Press 58 Appendix I: List of abbreviations used in this thesis and appendix II BPVS = British Picture Vocabulary Scale CD = clausal density CLAN = Corpus of Language & Nature CELF = Clinical evaluation of Language Fundamentals CG = control group CHI = congenital hearing impairment CNrep = the Children’s Non-word repetition task Con. D = conversational discourse Exp. D = expository discourse FGST = favourite game or sport task GM = grammatical morpheme HI = hearing impairment L2 = second language MLU = Mean Length of Utterance (in words) MLUL = Mean length of the (5) longest utterances MMHL = mild-t-moderate hearing loss MMSNHL = mild-to-moderate sensorineural hearing loss MSCHI = mild- to-severe congenital hearing impairment NH = normal hearing NLI = non-specific language impairment PRCT = peer conflict resolution task RE = Rolandic Epilepsy SALT = systematic analysis of language transcripts SLI = specific language impaired /impairment subo. = subordination synt. compl.= syntactic complexity TD = typically developed / developing TL = typical language TOLD = the Grammatical Completion subtest of the Test of Language development TROG = Test for Reception of Grammar V2 = verb second 59 Appendix II: Detailed information about the discussed studies Study Subjects + language Age Research topic / questions Task Results Delage, Monjauze, Hamann & Tuller (2008) SLI (N=21), MMHL (N=21), RE (N=11), 3 control groups (3 x N=12) AD 9;013;0 Is there an age effect in TD children? Do AD children show avoidance pattern “pseudo relatives” at higher rate and at older ages? Spontaneous language samples analyzed with CLAN An age effect was outlined in TD. AD used less complex structures, avoidance normal relatives. SLI avoided complex structures and had the highest error rate. RE scored like TD on subordination but like AD for avoidance. MMHL resembles SLI, but did produce normal relatives Delage & Tuller (2007) MMHL (N=19) TD (several) SLI (N=12) Adolescents 11;0-15;0 Do adolescents with HL display late normalization? - BILO - naming task - sentence completion task - reading timed task - word identification task - lexical judgement task - grammatical judgement task Language disorders in areas of phonology and grammar. No normalization with age in MMHL. Effect of severity of HL only after childhood Analysis of spontaneous language samples approximately 60 utterances per subject, using CLAN, Participants with MMHL tended to avoid finite embedded clauses and genuine relatives. Moreover, they produced failed attempts at embedding much more frequently than controls. Finally, when they produced complex utterances, they produced a great number of errors, especially in the most complex embedded clauses, i.e. in relative clauses. Control groups of 6;0, 8;0 and 11;0 Are there similarities (qual./ quan.) between MMHL and SLI language disorders in adolescents? (French) Delage & Tuller (2009) N=32 adolescents with MMHL (French) two age groups: N1=16 aged 6 to 9 N2=16 aged 9 to 11 Focuses on the evolution of syntactic complexity and the use of avoidance strategies in a population of children and adolescents with mild-tomoderate hearing loss (MMHL) 60 Study Subjects + language Age Research topic / questions Task Results Elfenbein, HardinJones & Davis (1994) MSCHI (N=40) 5;0 – 18;0 Describe oral communication skills of MSCHI children and adolescents - Test of articulation competence - Grammatical completion task - Interview MSCHI showed phonological problems and made syntactic errors. Their pragmatic errors consisted primarily of providing inadequate or ambiguous information to the listener. Spontaneous speech, language battery, cognitive battery Children with SLI produce less complex clauses than TD and much higher rate of these are ungrammatical. Adolescents did not produce significantly more subordination than children, suggesting that rates of embedding stagnate. The rate of ungrammatical utterances decreased, though not significant. Percentages of avoidance strategies (shallower embedding, direct speech) do not decrease with age in SLI, as they do in TD. Long-term effects of MSCHI in the domain of morpho-syntax; do MSCHI have a lower level of performance compared to NH adults? CELF-4 nl FGST Data show long term-effects of MSCHI in morpho-syntax. CELF-scores did not reveal any group differences. How moderate HI impacts on the use of GM’s in speech and to provide an explanation for pattern of findings Spontaneous speech, analyzed to determine the use of GM’s CG (N=16) MSCHI language skills compared to NH along a continuum Hamann, Tuller, Monjauze, Delage & Henry (2007) SLI children N=10 and adolescents N=18 children = 5;10 10;5 adolescents = 10;1115;7 Do children and adolescents with SLI have problems with computational complexity? Prediction: subordination will be difficult and will manifest itself with high error rates. TD controls (French) Huysmans, E., Jong, J. de, Lanschot-Wery J.H. van, Festen J.M. & S.T. Goverts (to appear) MSCHI (N=20) NH (N=10) McGuckian & Henry (2007) HI and and TD MLU matched control group (Dutch) (English) 3 control groups: age 6 / 8 /11 NH = 20;0 – 34;0 MSCHI = 20;0 – 45;0 Analysed by measures from STAP, completed with error categories, CD and CD for subo. Significant difference between HI and TD for 5 GM’s. No significant difference in accuracy order was found. Accuracy order of HI was characteristic of that of L2. 61 Study Subjects + language Age Research topic / questions Task Results Marinellie, S.A.(2004) SLI (N= 15) Mean age SLI 10;8 Differences between TL and SLI in syntactic complexity in ordinary language samples Spontaneous speech in conversational discourse. Concerns about the validity of conversational discourse for language sampling for syntactic complexity. SLI less complex than TL. TD (N=15) (Am. English) Mean age TD 10;0 Transcribed using SALT Nippold, M.A. (2009) 32 children playing chess. Mean age 10;11 Do different topics influence synt. compl. (English) 3 conversation types: -general - chess conv. - chess explanation Total T-units, ML, CD and use of subo. were higher in chess explanation than in general - and chess conversation. Chess knowledge was of no influence on language performance for any type of conversation. transcripts were analyzed for: ML/ T-unit, CD, subo. clause use. Nippold, M. A., L. J. Hesketh, J. K. Duthie, and T. C. Mansfield (2005) TD (N = 120) in 6 groups of 20 subjects. (English) 6 groups with mean ages: 8;1, 11;4, 13;9, 17;3, 25;6, 44;8 How does synt. dev. Differ in Con.D vs Exp.D? What markers for synt. growth exist in Con. D and Exp. D? Con. D about common topics vs. Exp. D elicited by a FGST Best indicators for synt. growth are ML/Tunit and rel. CD, with age relatedincrease into early adulthood. Total number of T-units increased with age. Large individual differences! - PCRT - FGST Older packed more info in their speech than younger speakers. PCR elicited more Exp. D than FGS. Changes in synt. dev. occur during adulthood. Levels of performance? Nippold, M.A., Mansfield T.C. and J.L. Billow (2007) TD (N=60) (English) 11;0, 17;0 and 25;0 Synt. compl. in Exp. D 62 Study Subjects + language Age Research topic / questions Task Results Nippold, M. A., T. C. Mansfield, J. L. Billow, and J. B. Tomblin (2008) SLI (N=106) NLI (N=84) TLD (N=254) Mean (controlled) age 13;11 Better use of syntax in NLI and SLI in expository over conversational discourse? - CELF - Language samples in Con. D and Exp.D analyzed for ML/ T-unit + subo. clause production MLU /T-unit and subo. use were greater during Exp.D for all groups. TLD outperformed NLI and SLI for MLU/ Tunit and NLI for relative clause production. Comparison between the performance of finite verb morphology of MMSNHL and SLI - BPVS - TROG - recalling sentence subtest of the CELF - CNrep - Finite Verb Morphology Task - Past Tense Elicitation Degree of hearing loss was not directly related to performance. Acquisition of finite verb morphology may be delayed in children with hearing impairment. Children with SLI produce unmarked stems in context where the inflection is obligatory more often. Would language sampling reveal syntactic deficits in NLI and SLI? (Am. English) Norbury, Bishop, & Briscoe (2001) MMSNHL (N=19) CG (N=20) SLI (N=14) CG (n=15) MMSNHL +CG age 5;9-10;7 SLI +CG age 7;210;9 Schick (1997) Profoundly deaf (N=13) (English) 7;1 - 14;8 Effects of discourse genre on complexity Spontaneous speech, narrative elicitation, interview through challenging questions. The most complex language was produced during the interview, measured by embedded clauses, conjunctions and modals. Utterance length did not vary as a function of sample type. Tuller, Henry, Sizaret & Barthez (2012) SLI, syntax, complexity, adolescents, avoidance N=18 SLI + control group Complex language in adolescents with SLI ; characteristic of typical syntactic development after childhood Spontaneous language samples Complexity increases with age in TD, behaviours of avoidance are clear in the SLI, in the form of low frequencies of complex structures, but also frequency of failed attempts and alternative strategies.Whereas increasing complexity is the hallmark of syntactic development after childhood, avoidance of complexity appears to characterize SLI after childhood. (French) Do individuals with SLI avoid using structures whose syntactic derivation involves greater computational complexity? 63 Appendix III: Research data name NH01 NH02 NH03 NH04 NH05 NH06 NH07 NH08 NH09 NH10 SH01 SH02 SH03 SH04 SH05 SH06 SH07 SH08 SH09 SH10 SH11 SH12 SH13 SH14 SH15 SH16 SH17 SH18 SH19 SH20 total number total number of analyzed 5 longest cl. T-units number T-units ML of t-unit T-unit 104,00 76,00 76,00 9,95 91,00 61,00 61,00 11,57 94,00 72,00 72,00 8,63 82,00 58,00 58,00 10,28 81,00 55,00 55,00 11,35 91,00 73,00 73,00 8,79 113,00 75,00 75,00 11,72 55,00 47,00 47,00 8,60 67,00 47,00 47,00 10,79 78,00 61,00 61,00 8,57 55,00 43,00 43,00 11,72 221,00 182,00 100,00 10,03 79,00 47,00 47,00 12,85 102,00 72,00 72,00 11,01 46,00 30,00 30,00 10,63 79,00 55,00 55,00 11,35 49,00 34,00 34,00 10,71 233,00 211,00 100,00 8,63 58,00 40,00 40,00 11,25 76,00 58,00 58,00 9,79 129,00 117,00 100,00 8,63 92,00 66,00 66,00 10,35 100,00 72,00 72,00 12,19 100,00 66,00 66,00 10,14 41,00 26,00 26,00 9,88 76,00 59,00 59,00 9,66 40,00 23,00 23,00 13,13 41,00 36,00 36,00 6,06 74,00 61,00 61,00 9,74 189,00 161,00 100,00 8,62 ML of 26,80 38,00 23,60 20,40 27,40 21,00 28,60 22,60 27,60 20,80 29,40 26,40 27,80 26,80 24,60 27,00 20,80 22,20 21,60 23,60 21,20 24,00 29,00 22,20 19,80 22,20 27,80 13,00 21,40 22,40 coordination subordination 48,00 28,00 39,00 30,00 23,00 22,00 23,00 24,00 21,00 26,00 48,00 18,00 46,00 38,00 16,00 8,00 30,00 20,00 16,00 17,00 29,00 12,00 31,00 39,00 30,00 32,00 36,00 30,00 17,00 16,00 41,00 24,00 13,00 15,00 35,00 22,00 9,00 18,00 21,00 18,00 44,00 12,00 30,00 26,00 63,00 28,00 37,00 34,00 15,00 15,00 33,00 17,00 14,00 17,00 14,00 5,00 30,00 13,00 57,00 28,00 64 name NH01 NH02 NH03 NH04 NH05 NH06 NH07 NH08 NH09 NH10 SH01 SH02 SH03 SH04 SH05 SH06 SH07 SH08 SH09 SH10 SH11 SH12 SH13 SH14 SH15 SH16 SH17 SH18 SH19 SH20 %nom %adv 14,29 40,00 40,91 37,50 38,46 27,78 26,32 37,50 30,00 35,29 41,67 33,33 43,75 13,33 6,25 62,50 26,67 22,73 22,22 27,78 33,33 30,77 53,57 64,71 6,67 23,53 58,82 20,00 46,15 21,43 %rel 85,71 33,33 54,55 33,33 30,77 55,56 39,47 62,50 45,00 58,82 33,33 58,97 12,50 73,33 87,50 25,00 46,67 45,45 61,11 61,11 25,00 30,77 28,57 11,76 66,67 70,59 41,18 80,00 53,85 57,14 CD % 0,00 26,67 4,55 29,17 30,77 16,67 34,21 0,00 25,00 5,88 25,00 7,69 43,75 13,33 6,25 12,50 26,67 31,82 16,67 11,11 41,67 38,46 17,86 23,53 26,67 5,88 0,00 0,00 0,00 21,43 rel. CD 1,37 1,49 1,31 1,41 1,47 1,25 1,51 1,17 1,43 1,28 1,28 1,39 1,68 1,42 1,53 1,44 1,44 1,22 1,45 1,31 1,12 1,39 1,39 1,52 1,58 1,29 1,74 1,14 1,21 1,28 adv. CD 1,00 1,13 1,01 1,12 1,15 1,04 1,17 1,00 1,11 1,02 1,07 1,03 1,30 1,06 1,03 1,05 1,12 1,07 1,08 1,03 1,05 1,15 1,07 1,11 1,15 1,02 1,00 1,00 1,00 1,06 nom. CD 1,32 1,16 1,17 1,14 1,15 1,14 1,20 1,11 1,19 1,16 1,09 1,23 1,09 1,31 1,47 1,11 1,21 1,10 1,28 1,19 1,03 1,12 1,11 1,08 1,38 1,20 1,30 1,11 1,11 1,16 1,05 1,20 1,13 1,16 1,18 1,07 1,13 1,06 1,13 1,10 1,12 1,13 1,30 1,06 1,03 1,27 1,12 1,05 1,10 1,09 1,04 1,12 1,21 1,33 1,04 1,07 1,43 1,03 1,10 1,06 65 name NH01 NH02 NH03 NH04 NH05 NH06 NH07 NH08 NH09 NH10 SH01 SH02 SH03 SH04 SH05 SH06 SH07 SH08 SH09 SH10 SH11 SH12 SH13 SH14 SH15 SH16 SH17 SH18 SH19 SH20 % % errors % errors ungram.sub. outside sub. inside sub. cl. % wrong % compl cl. cl. structure structure %wrong pro %pro. del compl. deletion %V2 3,57 3,57 0 0 0 0 0 0 3,33 0 3,33 0 0 0 0 3,333333333 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3,85 0 3,85 3,846153846 0 0 0 0 0 0 0 0 0 0 0 0 5,26 0 5,26 0 0 0 0 5,263157895 25 12,5 12,5 0 0 12,5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 16,67 16,67 0 0 0 0 0 0 56,41 53,85 17,95 0 2,564102564 7,692307692 2,564102564 5,128205128 6,25 3,125 3,125 3,125 0 0 0 0 0 0 0 0 0 0 0 0 6,25 0 6,25 0 0 0 0 6,25 12,5 8,33 4,17 0 0 0 0 4,166666667 20 0 20 6,666666667 6,666666667 0 0 6,666666667 4,55 0 4,55 0 0 4,545454545 0 0 11,11 11,11 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8,33 0 8,33 8,333333333 0 0 0 0 11,54 11,54 0 0 0 0 0 0 3,57 0 3,57 3,571428571 0 0 0 0 14,71 11,76 2,94 2,941176471 0 0 0 0 20 20 6,67 0 0 6,666666667 0 0 0 0 0 0 0 0 0 0 11,76 17,65 0 0 0 0 0 0 40 60 0 0 0 0 0 0 46,15 53,85 15,38 0 0 7,692307692 0 7,692307692 14,29 7,14 7,14 0 3,571428571 0 0 3,571428571 66 name NH01 NH02 NH03 NH04 NH05 NH06 NH07 NH08 NH09 NH10 SH01 SH02 SH03 SH04 SH05 SH06 SH07 SH08 SH09 SH10 SH11 SH12 SH13 SH14 SH15 SH16 SH17 SH18 SH19 SH20 %PV1 0 0 0 0 0 11,11111111 2,631578947 0 0 11,76470588 0 0 0 23,33333333 0 0 0 0 0 0 0 0 0 2,941176471 0 5,882352941 0 0 0 0 % direct speech 0,00 1,64 5,56 0,00 0,00 0,00 8,00 4,26 2,13 3,28 13,95 1,00 4,26 1,39 0,00 0,00 2,94 4,00 0,00 6,90 5,00 4,55 5,56 3,03 0,00 8,47 4,35 0,00 0,00 0,00 67