Download The Development of Nasal Consonants

The Development of Nasal Consonants
[m n] in Young Children
Kathryn M. Guillot & Ralph N. Ohde ♦ Vanderbilt University
Introduction
Measures
Speech perception of children is highly related to their
sensory hearing abilities (Geers et al., 2003; Jerger,
2007). Children with profound hearing loss are at a
particular disadvantage in developing adequate speech
perception. There is limited information regarding the
development of consonant and vowel perception in
children who use cochlear implants (CI). The
discontinuity hypothesis suggests that abrupt changes in
amplitude between the consonant and vowel provide
salient information in identification in adults. However,
there is no information on the perception of nasals in
children with and without cochlear implants.
Purpose
Results
Inclusion Measure
Pass a hearing screening
Arizona Test of Articulation
Descriptive Measure
Oral and Written Language Scales (OWLS)
Auditory Comprehension (AC)
Oral Expression (OE)
80
3. Does the performance of nasal identification in
children without hearing loss support the predictions
of the discontinuity hypothesis of speech
perception?
FS
MT
Vowels
OWLS
OE
OWLS
Oral
Composite
Arizona
i
24-33 yrs
N/A
N/A
N/A
N/A
Normal
Hearing
Older
(NHO)
8
75 mths
(11.4)
61-93
mths
106
(14)
111
(10)
109
(10)
100
(0.6)
Normal
Hearing
Younger
(NHY)
4
55.7 mths
(3.1)
53-59
mths
114
(13)
112
(7)
114
(11)
98
(1.1)
Cochlear
Implant (CI)
4
77.5 mths
(12.7)
61-88
mths
83
(18)
85
(17)
83
(18)
94
(8.0)
Adult
80
u
ae
YES. Children who use cochlear implants performed poorer than
children with normal hearing when identifying nasals within different
vowel context. An ANOVA revealed a main effect for vowel (i.e., I, æ,
u, ɑ), F(3, 12)= 5.210, p> .01 and a main effect for group (i.e., NHO,
NHY, CI), F(2, 13)= 25.794, p > .001.
Research Question 3: Does the performance of nasal
identification in children with normal hearing support the
discontinuity hypothesis of speech perception?
NHO
Percent Correct
a
Figure 3: Children’s performance on the vowels.
Research Question 1: Are there developmental changes in the
perception nasal segment conditions of 50 ms murmur, 50 ms
transition, and 25 ms murmur + 25 ms transition?
100
96
NHY
60
88
79
80
70
40
20
FS
28.6 yrs
(2.97)
NHO
NHY
CI
40
0
Results
0
8
60
Percent Correct
OWLS
LC
Children
Table 1:Participant Demographics
T
20
100
The children with normal hearing and who were between the ages of
3;6 to 7;11-years-old were recruited from Nashville area schools and
preschools. The children who use cochlear implants and who were
between the ages of 4;0 to 7;11-years-old were recruited from the
National Center for Childhood Deafness and Family Communication
at the Vanderbilt Bill Wilkerson Center. See Table 1 for participant
demographics.
Adult
M
YES. Children who use cochlear implants performed poorer than
children with normal hearing when identifying nasals segments. An
ANOVA revealed a main effect for nasal segment condition (i.e., M, T,
MT, FS), F(3, 12)= 40.769, p> .001 and a main effect for group (i.e.,
NHO, NHY, CI), F(2, 13)= 20.657, p > .001. There was a significant
interaction between group x nasal segment condition, F(6, 39)= 5.345,
p> .001.
Percent Correct
50-ms murmur (M)
25-ms murmur + 25-ms transition (MT)
50-ms transition (T)
full syllable (FS)
Participants
Age
Range
 murmur + transition (MT)
0
Figure 2: Children’s performance of nasal segment; M= 50 ms murmur; T= 50 ms transition; MT= 25 ms murmur + 25 ms transition
80
Figure 1. Spectrogram of the nasal consonant /nɑ] / representing the segment conditions.
M
T
60
40
MT
Figure 2: Comparison of groups across nasal segment conditions.
YES. We see developmental changes in the perception of nasal
segment conditions for younger and older children with normal hearing
compare to adults. An ANOVA revealed a main effect for nasal segment
condition (i.e., M, T, MT, FS), F(3, 16)= 44.429, p> .001 and a main effect
for group (i.e., adult, NHO, NHY), F(2, 17)= 14.472, p > .001. There was
a significant interaction between group x nasal segment condition, F(6,
51)= 6.239, p> .001.
 murmur (M)
 transition (T)
20
100
2. Do children who use cochlear implants identify
nasals comparable to children with normal hearing?
Mean Age
NHO
NHY
CI
40
The experimental task was a two-alternative forced-choice
testing paradigm with a total of 16 experimental conditions for
each participant. The speech stimuli consisted of nasal
consonant + vowel syllables comprised of [m n] and [i æ u ɑ]
and were developed and used in a previous study conducted
by Ohde et al. (2006).
1. Are there developmental changes in the perception
nasal segment conditions of 50 ms murmur, 50 ms
transition, and 25 ms murmur + 25 ms transition?
 There are developmental differences in the
identification of nasal consonants in children
with normal hearing. The younger children
performed differently than the older children
and adults in:
60
Research Questions:
n
Nasal Segments
100
The purpose of this study is to examine the
development of speech perception in children with and
without cochlear implants as a function of systematic
variation in place of articulation of nasal consonants.
Groups
Discussion
Research Question 2: Do children who use cochlear implants
identify nasals comparable to children with normal hearing?
20
 Children with normal hearing and children who
use cochlear implants can identify nasals [m n]
from a consonant-vowel [i æ u ɑ] syllable that
varies systematically in the acoustic correlates
of place of articulation.
 Children who use cochlear implants are less
accurate than children with normal hearing in
identifying CV syllables by segment type (i.e.,
M, T, MT) and by vowel type (i.e., [i æ u ɑ] ).
 The discontinuity hypothesis of speech
perception was supported by the performance
of the children with normal hearing. Children
process place of articulation with greater
accuracy for the MT segment than the other
acoustic conditions.
References
Jerger, S. (2007). Current state of knowledge: Perceptual
processing by children with hearing impairment. Ear and
Hearing, 28, 754-765.
Geers, A., Brenner, C. & Davidson, L. (2003). Factors
associated with development of speech perception skills
children implanted by age five. Ear and Hearing, 24, 24S35S.
Ohde, R.N., Haley, K.L. & Barns, C.W.(2006). Perception of the
[m]-[n] distinction in consonant-vowel (CV) and vowelconsonant (VC) syllables produced by child and adult
talkers. Journal of Acoustic Society of America ,119, 16971711.
0
FS
M
T
MT
Figure 5: Represents children with normal hearing on the nasal segment conditions.
YES. Children with normal hearing were more accurate in the murmur +
transition condition compared to the murmur only and transition only
condition. An ANOVA revealed a main effect for segment condition, F(3,
9)= 16.047, p> .001. Cohen d’s effect sizes were calculated for the following
conditions: MT vs T segment conditions, d= .62 and for MT vs M segment
conditions, d= 1.35.
Author contacts: [email protected]
[email protected]