Comparison of speech perception ab Iities in deaf children with hearing aids or cochlear implants RICHARD T. MIYAMOTO, MD, MARY JOE OSBERGER, PhD, AMY M. ROBBINS, MS, WENDY A. MYRES, MAT, KATHY KESSLER, MS, and MOLLY 1. POPE, MAT, Indianapolis, Indiana
The speech perception abilities of deaf children with a single- or multi-channel cochlear implant are compared with those of deaf children who derive substantial benefit from conventional hearing aids. The children with hearing aids have unaided pure-tone thresholds ranging from 90- to 110-dB HL through at least 2000 Hz, and aided thresholds of 30-to 60-dB HL. The group data show that the speech perception scores of the subjects with hearing aids were significantly higher than those of the subjects with implants on a range of speech perception measures. Although a few subjects with implants achieved scores as high as those who used hearing aids, the majority did not. Even though the children with implants receive substantial benefit from their devices, they continue to have limited auditory perception abilities relative to their peers who derive benefit from conventional hearing aids. The data highlight the importance of establishing hearing aid benefit in potential candidates for implant. (OTOLARYNGOL HEAD NECK SURG 1991;104:42.)
C h i l d r e n with profound sensorineural hearing loss demonstrate a wide range of speech perception abilities with conventional hearing aids. Clearly, not all are candidates for a cochlear implant. It is important to compare the performance of children with cochlear implants with that of children who derive substantial benefit from hearing aids on the basis of the same measures. These comparisons are needed to objectify criteria for implant candidacy. Published reports on the performance of deaf children with the single-channel 3Ml House device have documented the perception of those features of speech conveyed by temporal and intensity cues, such as perception of stress pattern, number of syllables, and differences in vowel height.' A small percentage of children with the 3M/House device demonstrate some open-set speech recognition on isolated word or sentence tests.* Initial reports on children who have received the Nucleus 22-channel implant are encouraging and From the Department of Otolaryngology-Head and Neck Surgery, Indiana University School of Medicine. Supported by NIH-NIDCD DC000415. Presented at the Annual Meeting of the American Neurotology Society, Palm Beach, Fla., April 27, 1990. Received for publication June 19, 1990; accepted Aug. 6 , 1990. Reprint requests: Richard T. Miyamoto, MD, Riley Hospital, Suite A-56, 702 Bamhill Dr., Indianapolis, IN 46202. 23I 1I24352
Table 1. Characteristics of subjects in speech perception study Ageat
Years
Device
N
onset
deaf
Years of use
3MiHouse Nucleus Hearing aid
11 11 12
1.4 1.2 1.1
5.8 6.3 2.1
1.4 1.7 5.7
demonstrate that open-set speech recognition can be achieved by some children. However, wide individual variations have already been observed. The purpose of this study is to evaluate the relative effectiveness of a single-channel or a multichannel cochlear implant in improving speech perception abilities of profoundly hearing-impaired children who derive negligible benefit from conventional hearing aids. The performance of subjects with cochlear implants is compared with that of profoundly hearing-impaired subjects who derive substantial benefit from hearing aids. Evaluating cochlear implant or hearing aid performance in young, profoundly hearing-impaired children is difficult because few standardized measures are available for very young and very deaf children. Performance is influenced by the child's linguistic abilities and previous experience and training with the device.
42 Downloaded from oto.sagepub.com at UNIV NEBRASKA LIBRARIES on June 9, 2016
Volume 104 Number 1 Januory 1991
Speech perception abilities in deaf children 43
FREQUENCY (Hzl 250
500
L”
.
30 40
50
.
.
.
,
.
.
.
.
.
,
.... . ,
. . .
1
. .
8ol
4000
*
,
.
60 70
2000
1000
.
,
. .~
.
,
.
.
. IPROFOUND HEARiNG . LdSS ‘4
1001
FUNCTIONAL HEARING
1201
TOTACLY D€AF
i
Fig. 1. Audiogram separating “profound hearing loss” into range of functional hearing and total deafness.
FREQUENCY (Hz) 250
500
1000
2000
4000
-10 0
2
n
10 20
30 40
w
1
UNAIDED T (PHONES)
ik
100
110 120
I
1
130 Fig. 2. Mean aided and unaided thresholds and standard deviations for 12 subjects who derived benefit from hearing aids.
SUBJECTS AND METHODS Subjects
A selected subset of children who use cochlear implants or hearing aids was chosen for this study (Table
1). The children were matched as closely as possible relative to age at onset of deafness, duration of deafness, and length of device use. The subjects, on average, had been using their devices for approximately
Downloaded from oto.sagepub.com at UNIV NEBRASKA LIBRARIES on June 9, 2016
Otolaryngology-
44 MWAMOTO et a1
Head and Neck Surgery
FEATURE DISCRIMINATION 1001
0 3M/HOUSE
0 NUCLEUS
COMPOSITE SHORT SCORE vs. LONG
GENDER
VOWEL HEIGHT
HEARING AID
VOWEL PLACE
MANNER
CHANGE/NO CHANGE Fig. 3. Change/No Change test. Mean scores averaged across nine subtests. Chance performance is indicated by broken line.
1.5 years at the time of data collection. Age at onset of deafness was slightly more than 1 year, and they had been deaf for approximately 6 years when they received their devices. Eleven subjects who use the 3M/House device and 11 who use the Nucleus 22-channel device participated in this study. Twelve profoundly deaf children who derive substantial benefit from conventional amplification served as the control group. The majority of the subjects with hearing aids had pure-tone averages in the 90- to 105-dB range and were considered to have functional hearing, whereas the subjects with cochlear implants had pre-implant pure-tone averages in excess of 110 dB and were considered totally deaf (Fig. 1). The means and ranges of the unaided and aided thresholds of the subjects with hearing aids are shown in Fig. 2. The length of hearing aid use is longer because hearing aids are fitted at the time of diagnosis of hearing loss. The selection process for subjects with cochlear implants includes a hearing aid trial and a demonstrated inability to benefit from conventional amplification. Methods
All subjects in the experimental groups received the same intensive training with their cochlear implants. Training was initiated immediately after the device was fitted and continued for the first 6 to 9 months of device
use. A minimum of 30 hours of individual rehabilitation focusing on auditory, speech, and language goals appropriate for each child was provided at the Indiana University Medical Center. The subjects with hearing aids received their training in their own school setting. A battery of test procedures was used to assess the subjects’ speech perception abilities. The tasks ranged from detection of sound to more complex discrimination, identification, and comprehension tasks. Discrimination test. The Change/No Change test is designed to assess a child’s ability to detect an acoustic change in a suprasegmental or segmental feature of speech. The children are required to identify changes in acoustic speech patterns, but are not required to label what they hear. The paradigm is based on that used to assess the speech perception skills of infants, as modified by Sussman and Carney.3The stimuli are nonsense syllables, spoken by an adult male, which were digitized and equalized for overall duration and intensity. The stimuli were recorded on audio tape and presented at a level of 70-dB SPL in the sound field. There are 10 subtests, each of which contrasts a particular feature of speech: syllable length (short vs. long), intonation (statement vs. question), fundamental frequency (steady vs. changing contour), speaker’s sex (male vs. female), vowel height (/bi/ vs /bu/), vowel placement
Downloaded from oto.sagepub.com at UNIV NEBRASKA LIBRARIES on June 9, 2016
Volume 104 Number 1 Januaw 1991
Speech perception abilities in deaf children 45
0 3M/HOUSE 1001 I
H
t-
V
W
a
a
0 V
I-
z
NUCLEUS
A TBw T
6ol
1001
-,-
-H
I-
V W
a n 0
V
40
I-
z
W
40
W
V
a
V
n W a
W
a
AUDITORY FEATURE IDENTIFICATION
0 HEARING AID
&
20
n "
STRESS PATTERN
20
WORD ID
3M/HOUSE
NUCLEUS
MONOSYLLABLE-TROCHEE-SPONOEE
Fig. 4. Monosyllable-Trochee-Spondeetest. Mean scores for stress pattern identification and word identification.
HEARING AID
GROUP
Fig. 5. Minimal Pairs test. Mean scores for auditory feature identification.
AUDITORY-VISUAL FEATURE INTEGRATION (/bi/ vs. /bu/), consonant manner (/da/ vs. /za/), consonant voicing (/ba/ vs. /pa/), and consonant placement (/ba/ vs. /ga/). Recognition tests. The Monosyllable-TrocheeSpondee (MTS) test4 consists of 12 pictured nouns with three different stress patterns. The child points to pictures of words as they are presented. Responses are scored in terms of percentages of correct identification of stress-pattern categorization and word identification. Chance performance on the stress-pattern categorization is 33% and on the word identification 8%. The Minimal Pairs test5 is a two-alternative forcedchoice test that consists of pairs of pictured words that differ in one phonetic feature (e.g., bear vs. pear). The test consists of 20 pairs of words, with each pair differing in one of the following features: vowel height, vowel place, consonant manner, consonant voice, or consonant place. All items are presented in the auditoryalone condition. The child points to the picture corresponding to the word spoken by the examiner. Chance level is 50%. The Hoosier Auditory Visual Enhancement (HAVE) test6 evaluates the child's ability to integrate visual and auditory information. The test consists of sets of three pictured items. Two items are homophonous or visually similar (e.g., man vs. pan), whereas the remaining one is visually distinct (e.g., fan). On a given trial, only one of the homophonous words is presented, but always with combined auditory and visual cues. The child points to the pictured item corresponding to the target word. Each item is scored on the basis of (1)
1001
0 3M/HOUSE
0 NUCLEUS
0 HEARING AID
I
0
L
Ji!#IzHAVE:WORD
HAVE:VISUAL
Fig. 6 . Hoosier Auditory Visual Enhancement test.Mean scores indicate integration of auditory and visual information.
visual correctness (HAVE: Visual) and ( 2 ) word correctness (HAVE: Word). There are 20 sets of words. RESULTS
Auditory discrimination of speech features as measured by the Change/No Change test is illustrated in Fig. 3; stress pattern identification and closed-set word identification as measured by the MTS test are illustrated in Fig. 4; auditory feature identification as measured by the Minimal Pairs test is illustrated in Fig. 5; and results of auditory-visual feature integration as measured by the HAVE test are illustrated in Fig. 6.
Downloaded from oto.sagepub.com at UNIV NEBRASKA LIBRARIES on June 9, 2016
OtolaryngologyHead and Neck Surgery
46 MlYAMOTO er ai.
Above-chance performance was observed with all three devices throughout the subtests. Users of the Nucleus 22-channel device as a group outperformed users of the single-channel device. However, subjects who were able to use conventional amplification performed the best. They were able to achieve near-perfect scores on all test measures designed to assess this population.
DISCUSSION There is an urgent need to accurately assess the influence of cochlear implants and other sensory aids on the acquisition of communication skills. Deaf children typically develop these skills slowly and with great difficulty. A wide range of capabilities has been documented and progress is variable between subjects. However, mean data demonstrate a trend suggesting that cochlear implants can provide salient speech cues to the deafened child. An advantage of multi-channel stimulation over single-channel stimulation in the acquisition of speech perception skills seems apparent. However, even those children with multi-channel cochlear implants continued to have limited auditory speech perception abilities and required hearing-impaired rehabilitative services. Detailed longitudinal information is required because only through this documentation can the full impact of cochlear implantation be established. Performance was clearly superior with hearing aids when the subjects were able to benefit from conventional amplification. This superiority was observed irrespective of the response task or type of stimulus. These findings are not surprising, given the aided auditory thresholds. At this time it appears that most children with pure-tone thresholds between 90 to 105 dB and residual hearing throughout the frequency range will derive more benefit from conventional amplification than from even a multi-channel cochlear implant. It is evident that speech perception measures must be
included in the test battery when evaluating a child for cochlear implant candidacy who is able to benefit from amplification. The subjects with cochlear implants who participated in this study demonstrated poorer performance than the control group with hearing aids. However, they achieved significantly higher levels of performance with their cochlear implants than they were able to achieve with conventional hearing aids. Although not reflected in the group data reported here, there are some subjects in our larger population with a single- or multi-channel cochlear implant who achieved scores similar to those of subjects with hearing aids in this study. These children tended to have a later onset of deafness (i.e., after 5 years of age) than the subjects included in this study. We wish to thank Stacey Berry, Susan Todd, Leslie Sam, and Terri Kerr for their assistance in the management of the children and collection and analyses of the data.
REFERENCES 1. Thielemeier MA, Tonokawa LL, Petersen B, Eisenberg L. Audiological results in children with a cochlear implant. Ear Hear 1985;6:27S-35/sm. 2. Berliner KI, Tonokawa LL, Dye LM, House WF. Open-set speech recognition in children with a single-channel cochlear implant. Ear Hear 1989;10:237-42. 3. Sussman JE, Carney AE. Effects of transition length on perception of stop consonants by children and adults. J Speech Hear Res 1989;32:151-60. 4. Erber NP, Alencewicz CM. Audiologic evaluation of deaf children. J Speech Hear Res 1972;41:252-67. 5. Robbins AM, Renshaw JJ, Miyamoto RT, Osberger MJ, Pope ML. Minimal Pairs Test. Indianapolis: Indiana University School of Medicine, 1988. 6 . Renshaw JJ, Robbins AM, Miyamoto RT, Osberger MJ, Pope ML. Hoosier Auditory Visual Enhancement Test (HAVE). Indianapolis: Indiana University School of Medicine, 1988.
Downloaded from oto.sagepub.com at UNIV NEBRASKA LIBRARIES on June 9, 2016
The speech perception abilities of deaf children with a single- or multi-channel cochlear implant are compared with those of deaf children who derive substantial benefit from conventional hearing aids. The children with hearing aids have unaided pure-tone thresholds ranging from 90- to 110-dB HL through at least 2000 Hz, and aided thresholds of 30-to 60-dB HL. The group data show that the speech perception scores of the subjects with hearing aids were significantly higher than those of the subjects with implants on a range of speech perception measures. Although a few subjects with implants achieved scores as high as those who used hearing aids, the majority did not. Even though the children with implants receive substantial benefit from their devices, they continue to have limited auditory perception abilities relative to their peers who derive benefit from conventional hearing aids. The data highlight the importance of establishing hearing aid benefit in potential candidates for implant. (OTOLARYNGOL HEAD NECK SURG 1991;104:42.)
C h i l d r e n with profound sensorineural hearing loss demonstrate a wide range of speech perception abilities with conventional hearing aids. Clearly, not all are candidates for a cochlear implant. It is important to compare the performance of children with cochlear implants with that of children who derive substantial benefit from hearing aids on the basis of the same measures. These comparisons are needed to objectify criteria for implant candidacy. Published reports on the performance of deaf children with the single-channel 3Ml House device have documented the perception of those features of speech conveyed by temporal and intensity cues, such as perception of stress pattern, number of syllables, and differences in vowel height.' A small percentage of children with the 3M/House device demonstrate some open-set speech recognition on isolated word or sentence tests.* Initial reports on children who have received the Nucleus 22-channel implant are encouraging and From the Department of Otolaryngology-Head and Neck Surgery, Indiana University School of Medicine. Supported by NIH-NIDCD DC000415. Presented at the Annual Meeting of the American Neurotology Society, Palm Beach, Fla., April 27, 1990. Received for publication June 19, 1990; accepted Aug. 6 , 1990. Reprint requests: Richard T. Miyamoto, MD, Riley Hospital, Suite A-56, 702 Bamhill Dr., Indianapolis, IN 46202. 23I 1I24352
Table 1. Characteristics of subjects in speech perception study Ageat
Years
Device
N
onset
deaf
Years of use
3MiHouse Nucleus Hearing aid
11 11 12
1.4 1.2 1.1
5.8 6.3 2.1
1.4 1.7 5.7
demonstrate that open-set speech recognition can be achieved by some children. However, wide individual variations have already been observed. The purpose of this study is to evaluate the relative effectiveness of a single-channel or a multichannel cochlear implant in improving speech perception abilities of profoundly hearing-impaired children who derive negligible benefit from conventional hearing aids. The performance of subjects with cochlear implants is compared with that of profoundly hearing-impaired subjects who derive substantial benefit from hearing aids. Evaluating cochlear implant or hearing aid performance in young, profoundly hearing-impaired children is difficult because few standardized measures are available for very young and very deaf children. Performance is influenced by the child's linguistic abilities and previous experience and training with the device.
42 Downloaded from oto.sagepub.com at UNIV NEBRASKA LIBRARIES on June 9, 2016
Volume 104 Number 1 Januory 1991
Speech perception abilities in deaf children 43
FREQUENCY (Hzl 250
500
L”
.
30 40
50
.
.
.
,
.
.
.
.
.
,
.... . ,
. . .
1
. .
8ol
4000
*
,
.
60 70
2000
1000
.
,
. .~
.
,
.
.
. IPROFOUND HEARiNG . LdSS ‘4
1001
FUNCTIONAL HEARING
1201
TOTACLY D€AF
i
Fig. 1. Audiogram separating “profound hearing loss” into range of functional hearing and total deafness.
FREQUENCY (Hz) 250
500
1000
2000
4000
-10 0
2
n
10 20
30 40
w
1
UNAIDED T (PHONES)
ik
100
110 120
I
1
130 Fig. 2. Mean aided and unaided thresholds and standard deviations for 12 subjects who derived benefit from hearing aids.
SUBJECTS AND METHODS Subjects
A selected subset of children who use cochlear implants or hearing aids was chosen for this study (Table
1). The children were matched as closely as possible relative to age at onset of deafness, duration of deafness, and length of device use. The subjects, on average, had been using their devices for approximately
Downloaded from oto.sagepub.com at UNIV NEBRASKA LIBRARIES on June 9, 2016
Otolaryngology-
44 MWAMOTO et a1
Head and Neck Surgery
FEATURE DISCRIMINATION 1001
0 3M/HOUSE
0 NUCLEUS
COMPOSITE SHORT SCORE vs. LONG
GENDER
VOWEL HEIGHT
HEARING AID
VOWEL PLACE
MANNER
CHANGE/NO CHANGE Fig. 3. Change/No Change test. Mean scores averaged across nine subtests. Chance performance is indicated by broken line.
1.5 years at the time of data collection. Age at onset of deafness was slightly more than 1 year, and they had been deaf for approximately 6 years when they received their devices. Eleven subjects who use the 3M/House device and 11 who use the Nucleus 22-channel device participated in this study. Twelve profoundly deaf children who derive substantial benefit from conventional amplification served as the control group. The majority of the subjects with hearing aids had pure-tone averages in the 90- to 105-dB range and were considered to have functional hearing, whereas the subjects with cochlear implants had pre-implant pure-tone averages in excess of 110 dB and were considered totally deaf (Fig. 1). The means and ranges of the unaided and aided thresholds of the subjects with hearing aids are shown in Fig. 2. The length of hearing aid use is longer because hearing aids are fitted at the time of diagnosis of hearing loss. The selection process for subjects with cochlear implants includes a hearing aid trial and a demonstrated inability to benefit from conventional amplification. Methods
All subjects in the experimental groups received the same intensive training with their cochlear implants. Training was initiated immediately after the device was fitted and continued for the first 6 to 9 months of device
use. A minimum of 30 hours of individual rehabilitation focusing on auditory, speech, and language goals appropriate for each child was provided at the Indiana University Medical Center. The subjects with hearing aids received their training in their own school setting. A battery of test procedures was used to assess the subjects’ speech perception abilities. The tasks ranged from detection of sound to more complex discrimination, identification, and comprehension tasks. Discrimination test. The Change/No Change test is designed to assess a child’s ability to detect an acoustic change in a suprasegmental or segmental feature of speech. The children are required to identify changes in acoustic speech patterns, but are not required to label what they hear. The paradigm is based on that used to assess the speech perception skills of infants, as modified by Sussman and Carney.3The stimuli are nonsense syllables, spoken by an adult male, which were digitized and equalized for overall duration and intensity. The stimuli were recorded on audio tape and presented at a level of 70-dB SPL in the sound field. There are 10 subtests, each of which contrasts a particular feature of speech: syllable length (short vs. long), intonation (statement vs. question), fundamental frequency (steady vs. changing contour), speaker’s sex (male vs. female), vowel height (/bi/ vs /bu/), vowel placement
Downloaded from oto.sagepub.com at UNIV NEBRASKA LIBRARIES on June 9, 2016
Volume 104 Number 1 Januaw 1991
Speech perception abilities in deaf children 45
0 3M/HOUSE 1001 I
H
t-
V
W
a
a
0 V
I-
z
NUCLEUS
A TBw T
6ol
1001
-,-
-H
I-
V W
a n 0
V
40
I-
z
W
40
W
V
a
V
n W a
W
a
AUDITORY FEATURE IDENTIFICATION
0 HEARING AID
&
20
n "
STRESS PATTERN
20
WORD ID
3M/HOUSE
NUCLEUS
MONOSYLLABLE-TROCHEE-SPONOEE
Fig. 4. Monosyllable-Trochee-Spondeetest. Mean scores for stress pattern identification and word identification.
HEARING AID
GROUP
Fig. 5. Minimal Pairs test. Mean scores for auditory feature identification.
AUDITORY-VISUAL FEATURE INTEGRATION (/bi/ vs. /bu/), consonant manner (/da/ vs. /za/), consonant voicing (/ba/ vs. /pa/), and consonant placement (/ba/ vs. /ga/). Recognition tests. The Monosyllable-TrocheeSpondee (MTS) test4 consists of 12 pictured nouns with three different stress patterns. The child points to pictures of words as they are presented. Responses are scored in terms of percentages of correct identification of stress-pattern categorization and word identification. Chance performance on the stress-pattern categorization is 33% and on the word identification 8%. The Minimal Pairs test5 is a two-alternative forcedchoice test that consists of pairs of pictured words that differ in one phonetic feature (e.g., bear vs. pear). The test consists of 20 pairs of words, with each pair differing in one of the following features: vowel height, vowel place, consonant manner, consonant voice, or consonant place. All items are presented in the auditoryalone condition. The child points to the picture corresponding to the word spoken by the examiner. Chance level is 50%. The Hoosier Auditory Visual Enhancement (HAVE) test6 evaluates the child's ability to integrate visual and auditory information. The test consists of sets of three pictured items. Two items are homophonous or visually similar (e.g., man vs. pan), whereas the remaining one is visually distinct (e.g., fan). On a given trial, only one of the homophonous words is presented, but always with combined auditory and visual cues. The child points to the pictured item corresponding to the target word. Each item is scored on the basis of (1)
1001
0 3M/HOUSE
0 NUCLEUS
0 HEARING AID
I
0
L
Ji!#IzHAVE:WORD
HAVE:VISUAL
Fig. 6 . Hoosier Auditory Visual Enhancement test.Mean scores indicate integration of auditory and visual information.
visual correctness (HAVE: Visual) and ( 2 ) word correctness (HAVE: Word). There are 20 sets of words. RESULTS
Auditory discrimination of speech features as measured by the Change/No Change test is illustrated in Fig. 3; stress pattern identification and closed-set word identification as measured by the MTS test are illustrated in Fig. 4; auditory feature identification as measured by the Minimal Pairs test is illustrated in Fig. 5; and results of auditory-visual feature integration as measured by the HAVE test are illustrated in Fig. 6.
Downloaded from oto.sagepub.com at UNIV NEBRASKA LIBRARIES on June 9, 2016
OtolaryngologyHead and Neck Surgery
46 MlYAMOTO er ai.
Above-chance performance was observed with all three devices throughout the subtests. Users of the Nucleus 22-channel device as a group outperformed users of the single-channel device. However, subjects who were able to use conventional amplification performed the best. They were able to achieve near-perfect scores on all test measures designed to assess this population.
DISCUSSION There is an urgent need to accurately assess the influence of cochlear implants and other sensory aids on the acquisition of communication skills. Deaf children typically develop these skills slowly and with great difficulty. A wide range of capabilities has been documented and progress is variable between subjects. However, mean data demonstrate a trend suggesting that cochlear implants can provide salient speech cues to the deafened child. An advantage of multi-channel stimulation over single-channel stimulation in the acquisition of speech perception skills seems apparent. However, even those children with multi-channel cochlear implants continued to have limited auditory speech perception abilities and required hearing-impaired rehabilitative services. Detailed longitudinal information is required because only through this documentation can the full impact of cochlear implantation be established. Performance was clearly superior with hearing aids when the subjects were able to benefit from conventional amplification. This superiority was observed irrespective of the response task or type of stimulus. These findings are not surprising, given the aided auditory thresholds. At this time it appears that most children with pure-tone thresholds between 90 to 105 dB and residual hearing throughout the frequency range will derive more benefit from conventional amplification than from even a multi-channel cochlear implant. It is evident that speech perception measures must be
included in the test battery when evaluating a child for cochlear implant candidacy who is able to benefit from amplification. The subjects with cochlear implants who participated in this study demonstrated poorer performance than the control group with hearing aids. However, they achieved significantly higher levels of performance with their cochlear implants than they were able to achieve with conventional hearing aids. Although not reflected in the group data reported here, there are some subjects in our larger population with a single- or multi-channel cochlear implant who achieved scores similar to those of subjects with hearing aids in this study. These children tended to have a later onset of deafness (i.e., after 5 years of age) than the subjects included in this study. We wish to thank Stacey Berry, Susan Todd, Leslie Sam, and Terri Kerr for their assistance in the management of the children and collection and analyses of the data.
REFERENCES 1. Thielemeier MA, Tonokawa LL, Petersen B, Eisenberg L. Audiological results in children with a cochlear implant. Ear Hear 1985;6:27S-35/sm. 2. Berliner KI, Tonokawa LL, Dye LM, House WF. Open-set speech recognition in children with a single-channel cochlear implant. Ear Hear 1989;10:237-42. 3. Sussman JE, Carney AE. Effects of transition length on perception of stop consonants by children and adults. J Speech Hear Res 1989;32:151-60. 4. Erber NP, Alencewicz CM. Audiologic evaluation of deaf children. J Speech Hear Res 1972;41:252-67. 5. Robbins AM, Renshaw JJ, Miyamoto RT, Osberger MJ, Pope ML. Minimal Pairs Test. Indianapolis: Indiana University School of Medicine, 1988. 6 . Renshaw JJ, Robbins AM, Miyamoto RT, Osberger MJ, Pope ML. Hoosier Auditory Visual Enhancement Test (HAVE). Indianapolis: Indiana University School of Medicine, 1988.
Downloaded from oto.sagepub.com at UNIV NEBRASKA LIBRARIES on June 9, 2016
