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-1- Effects on specific auditory stimulation on language processing Introduction: At the Secondary School BC Broekhin Roermond has been carried out a Pilot Study about the possible effects of specific auditory stimulation on language processing. This study needs some international comparison to find out if children from other countries and other languages also can benefit from this specific auditory stimulation. Three schools from Norway, Sweden and Italy are interested in a similar study. Is it possible to make use of a subsidy to finance this study in the next two years? Purpose of the study: The recent developments in understanding our auditory perceptual abilities, their development, their disruption and their relation to language ability, have led some clinicians, educators and researchers to suggest that it might be possible to train or stimulate the auditory system in individuals with language problems in such a way that their perceptual abilities improve and that such stimulation after some time may also have an effect on language production (Merzenich et al. 1996; Tallal et al. 1996). Tallal et al. (1981) concluded that many language problems in school are a result of auditory perceptual impairments, particularly in temporal aspects of sound recognition. An area of interest was the effective use of acoustically modified speech and adapted neuroplasticity training to improve language processing (Tallal et al. 1996 and Merzenich et al. 1996). This conclusion led to a focus on strengthening the relevant neural pathways through modified presentation of acoustic stimuli (Tallal & Merzenich, 1997). Moncrieff & Wertz (2001) trained children with left ear deficits intensively in two phases of dichotic listening training. In phase I and II children showed improved dichotic listening after training. A promising additional finding was that by phase II, subjects were also showing significant improvements in language comprehension and word recognition. The purpose of this Pilot Study was to determine whether often heard claims from teachers and parents, that some methods of non-verbal auditory stimulation are beneficial for some students, could be validated. For more than fifty years a very large number of therapists and educators in Europe and in North America have found that specific non-verbal stimulations with music and/or sounds seem to have beneficial effects on language and learning impaired students’ development when used to support remedial teaching. I found that the stimulation method developed in Denmark by Dr. Kjeld V. Johansen was addressing each individual student’s needs and at the same time made it possible to control development during the stimulation period so rigorously that this system was optimally suited for a controlled study. Research questions: What are the effects of HSAS (Hemisphere Specific Auditory Stimulation) on language in dyslexic students (compared to a control-group of dyslexic students and a control-group of non-dyslexic students initially at the same level) in: -reading -spelling -writing -rapid naming -memory Study: “Effects on specific auditory stimulation on language processing ”. -2-phonemic analysis -hearing curves -auditory laterality -What are the effects on attention/concentration, co-ordination and behaviour. -Is there an effect on automaticity of any kind (like tying shoelaces, learning computer games, etc.), not concerning the items mentioned above. Description of the study: Subjects In this pilot study we worked with 28 pupils (age 13-17) divided into three groups. Two groups (1 and 2) of pupils (N=10, f: 3, m: 7) diagnosed as dyslexic and one group (N=8, f: 3, m: 5) of non-dyslexic pupils. All pupils and their parents gave oral and/or written consent to participate in the study. To get a well-balanced classification of three, qua level, equal groups the following criteria were considered: -age -grade -gender -total IQ -verbal IQ -performance IQ -technical reading (decoding) -reading comprehension -spelling -mathematics / calculation. This information was obtained from the pupils’ personal files. (It was extremely difficult to find dyslexic and non-dyslexic pupils with the same levels in mathematics / calculation). Subgroup 1 had: 7 right-hander’s, 1 left hander and 2 ambidextrous, group 2: 10 righthander’s and group 3: 5 right hander’s, 1 lefthander and 2 ambidextrous. Subgroup 1 (the treatment group) was formed after talks with the pupils and their parents where the pupils stated that they were willing to listen for 10 min. a day through the full training period and where the parents agreed to supervise. Based on the data from these tests an analysis of variance (ANOVA) was performed between the three groups involved in the experiment: Group 1: Dyslexics with special remedial education and auditory stimulation. Group 2: Dyslexics only with special remedial education. Group 3: Non-dyslexics. Tests used The following skills were tested before and after the period of auditory stimulation. All three groups were tested with the same tests. Technical Reading (decoding) Reading comprehension Spelling Study: “Effects on specific auditory stimulation on language processing ”. -3Writing / copying Auditory memory Visual memory Phonemic Analysis Rapid Naming Audiometric testing including: Audiogram (hearing curves of R and L ear) Auditory Laterality (Binaural Pure Tone Audiometry / Dichotic Listening) Completed with: Parent and student questionnaires (group 1) on attention, behaviour, concentration and automaticity. Technical equipment The audiometric assessments were carried out using a computer based, calibrated audiometer developed by Mediacenter Mjölby, Sweden. The audiometer (to determine the hearing thresholds of the R and L ear) is placed on an Acer Travel Mate 662LCi using Telephonics TDH-39P earphones. Calibration showed less than 0.1% deviance on any frequency and less than 0.5% deviance on any dB level. Also on the computer (called a Sensograph, SG) is a dichotic listening test developed by Baltic Dyslexia Research Lab. Method of stimulation Based on the audiometric assessment a CD with selected music is recorded on the computer. The audiometric data are transported to a built-in equalizer (part of the SG) which applies an audiometric adjustment procedure by which the amplitude for each frequency is lowered or raised to fit pre-programmed reference values. Each pupil listened to a number of individually customized CDs in periods of 8-12 weeks. Listening to the CD takes place via stereo earphones at home for 10 min. a day. The pupil listens in a relaxed state either sitting or lying down. The type of CD player does not seem crucial while the type of earphone does. (Some earphones give an extra boost in the lower frequencies. This influences the music on the CD.) For this study all participants used Sennheiser HD477. Each recording was based on an audiogram made just before the customization took place. In the recording process the SG uses pre-programmed levels as reference values, referred to as the optimum hearing curve, (OHC) (Johansen, 2002; Tomatis, 1963, pg. 101). OHC: 125 Hz: 20dB, 250 Hz: 15 dB, 500 Hz: 12 dB, 750 Hz: 10 dB, 1000 Hz: 5 dB, 1500 Hz: 0 dB, 2000 Hz: -5 dB, 3000 Hz: -10 dB, 4000 Hz: -10 dB, 6000 Hz: -5 dB, 8000 Hz; 0 dB. After a period of 8-12 weeks the pupil is re-assessed and a new recording following the same principles is made. Some pupils will need 3-4 CDs, others will need as many as 8-10 CDs. In this pilot study the average number of CDs used was 8. In the study reported by Johansen (2002) the average length of the stimulation period was 29 weeks ranging from 10 weeks to 65 weeks. The music The music used has been designed especially for Hemisphere Specific Auditory Stimulation (HSAS) by Bent-Peder Holbech and Kjeld Johansen and has been in use since 1984. Initially it was produced on individually recorded cassette tapes but is now produced on individually customized CDs. Each CD contains 60 minutes of music selected and combined from a number of 5 or 10 minute compositions each in a narrow frequency range (1½ octaves), using the seven major keys and with 60 beats per minute. In total the frequency range 50 Hz to 12000 Hz is covered. To ease the customization and recording process all music is stored on Study: “Effects on specific auditory stimulation on language processing ”. -4the hard disk of the SG. The selection of the right music for each individual pupil is a professional task. Data analysis Comparisons between the three groups showed significant variances in the following areas: Sound processing (Klepel non-word test and phonemic analysis). Not surprisingly, group 3 showed the best results initially (higher score on non-words and less errors in phonemic analysis), but this group showed no improvements during the period. Groups 1 and 2 both improved and the improvements in group 1 reached statistical significance. Technical reading/decoding (EMT and reading aloud). Results from these tests again showed that group 3 had higher scores but fewer improvements than group 1 on EMT and than group 1 and 2 on reading aloud. On both tests the results from group 1 reached statistical significance. Spelling. The improvement in group 1 reached statistical significance. Group 2 showed improvement as well but group 3 did not improve. Information processing (rapid naming). The total scores from group 1 showed significant improvement. Groups 2 and 3 also showed improvements, but the results did not reach statistical significance. Six out of eight subtests administered to group 1 showed statistically significant improvements. Two subtests (letter naming and color naming) showed no statistically significant improvements in group 1, but in the color naming subtest a larger improvement was found in group 1 than in group 2 or group 3. Visual memory. Groups 1 and 2 both showed statistically significant improvements. Group 3 also showed improved results. The improvements found in group 1 were the largest. Audiometry. Hearing curves for left and right ear. Hearing curves for group 1 improved very significantly compared to the two other groups. Improvement of hearing (altered sensitivity) is part of the theory behind HSAS. Auditory laterality. Dichotic listening test. A statistically significant improvement for the right ear was seen in group 1. Group 3 also showed a significant improvement, but most of the pupils in this group already showed a right ear advantage (REA) from the beginning. Obtaining or improving REA is also part of the underlying theory behind HSAS. On the following subtests no statistically significant improvements were found in group 1: Reading comprehension (total score). On the pretest group 3 scored less than group 1 and 2, but this group had a statistically significant improvement from pre- to post-test. Groups 1 and 2 also showed improved results but they did not reach statistical significance. (It is interesting to note that in the result “macro score” for reading comprehension group 1 showed more improvement than did group 2 and 3. In “micro score” as well as in “meso score” the opposite results were found). Writing/copying. Group 1 showed a larger improvement than group 2 and 3 but the result did not reach statistical significance. The results from group 3 were, according to pre- and post tests better than the results from group 1 and 2, but interestingly showed a slight decrease from pre- to post test. Auditory memory. No group had statistically significant improvements. Group 3 even had a decrease in score from pre- to post test. From earlier studies it is known that the Johansen Sound Therapy can improve reading and spelling. However, dyslexics can have problems in other areas. Therefore, other tests were involved in this study. It wasn’t surprising to find significant improvement with reading and spelling. Remarkable was the improvement on sound processing and information processing. These processing abilities are fundamental for reading and spelling. Very remarkable was the Study: “Effects on specific auditory stimulation on language processing ”. -5significant improvement of visual memory. The visual and auditory centers in the brain are situated closely to each other. (Together with the motoric centre). Indirectly these areas are also stimulated by this therapy. Most remarkable was that the auditory memory didn’t improve significantly. On the other hand writing / copying improved significantly as well. Reading comprehension did improve, but not significantly. I thought that, after this treatment, the students would have enough tools to improve this as well. Probably this is not the case. Reading still can be seen as an unavoidable task that often is carried out without motivation and enthusiasm. Conclusion: Dyslexics most often show impaired phonological processing. Some research has concentrated on the temporal aspects of language sounds (Merzenich et al., 1993) while others have looked more at the categorical perception of vowel sounds (Bertucci et al., 2003). To our knowledge few researchers have tried to link ear advantage and even fewer basic auditory skills in the perception of pure tones at different frequencies to language development and to language problems including specific reading and spelling difficulties. This project shows that statistically significant improvements in auditory sensitivity documented by altered audiograms and statistically significant changes of auditory laterality documented by dichotic listening, obtained by non-verbal auditory stimulation, are accompanied by statistically significant improvements in decoding, spelling, reading aloud, phonemic analysis, rapid naming, visual memory and behavior. More research addressing individuals with different auditory and visual profiles is necessary, especially in other language areas, but this pilot study seems to indicate that carefully planned intervention using an empirical method with selected individuals suffering from specific sensory problems alongside with dyslexia may be beneficial. The Johansen-IAS therapy is successfully applied at our school. There is an international interest in this therapy. It would be of a great value to have the possibility to compare our results with results obtained abroad. We hope that students with language problems from different European countries can benefit from this therapy to have a successful school career. Wim de Zwart, MA Remediaal Specialist – Johansen-IAS therapist BC Broekhin Roermond Study: “Effects on specific auditory stimulation on language processing ”.