Benefits of incorporating the adaptive dynamic range optimization amplification scheme into an assistive listening device for people with mild or moderate hearing loss.

This study investigated whether a self-designed assistive listening device (ALD) that incorporates an adaptive dynamic range optimization (ADRO) amplification strategy can surpass a commercially available monaurally worn linear ALD, SM100. Both subjective and objective measurements were implemented. Mandarin Hearing-In-Noise Test (MHINT) scores were the objective measurement, whereas participant satisfaction was the subjective measurement. The comparison was performed in a mixed design (i.e., subjects' hearing status being mild or moderate, quiet versus noisy, and linear versus ADRO scheme). The participants were two groups of hearing-impaired subjects, nine mild and eight moderate, respectively. The results of the ADRO system revealed a significant difference in the MHINT sentence reception threshold (SRT) in noisy environments between monaurally aided and unaided conditions, whereas the linear system did not. The benchmark results showed that the ADRO scheme is effectively beneficial to people who experience mild or moderate hearing loss in noisy environments. The satisfaction rating regarding overall speech quality indicated that the participants were satisfied with the speech quality of both ADRO and linear schemes in quiet environments, and they were more satisfied with ADRO than they with the linear scheme in noisy environments.

A test protocol for assessing the hearing status of students with special needs.

OBJECTIVES: Individuals with disabilities are often reported to have a high prevalence of undetected hearing disorders/loss, but there is no standardized hearing test protocol for this population. The purposes of this study were (1) to examine the hearing status of students with special needs in Taiwan, and (2) to investigate the use of an on-site hearing test protocol that would adequately detect hearing problems in this population and reduce unnecessary referrals for off-site follow-up services. METHODS: A total of 238 students enrolled in two schools for special education and one habilitation center participated in the study. Most students had intellectual disabilities and some also had additional syndromes or disorders. A hearing screening protocol including otoscopy, tympanometry, and distortion product otoacoustic emissions was administered to examine students' outer, middle, and inner ear functions, respectively. Pure tone tests were then administered as an on-site follow-up for those who failed or could not be tested using the screening protocol. RESULTS: Only 32.4% of students passed. When administered alone, the referral rate of otoscopy, tympanometry, and otoacoustic emissions were 38.7%, 46.0%, and 48.5%, respectively. The integration of these subtests revealed 52.1% of students needed follow-up services, 11.8% could not be tested, 2.5% had documented hearing loss, and 1.3% needed to be monitored because of negative middle ear pressure. The inclusion of pure tone audiometry increased the passing rate by 9.9% and provided information on hearing sensitivity for an additional 8.6% of students. CONCLUSION: Hearing assessments and regular hearing screening should be provided as an integral part of health care services for individuals with special needs because of high occurrences of excessive cerumen, middle ear dysfunction, and sensorineural hearing loss. The training of care-givers and teachers of students with special needs is encouraged so that they can help identify hearing problems and reduce the negative impact of hearing disorders and hearing loss. The screening protocol needs to include subtests that examine the status of different parts of their auditory system. The addition of pure tone audiometry as an on-site follow-up tool reduced the rate of off-site referrals and provided more information on hearing sensitivity.

Auditory performance and speech intelligibility of Mandarin-speaking children implanted before age 5.

OBJECTIVES: (1) To report the auditory performance and speech intelligibility of 84 Mandarin-speaking prelingually deaf children after using cochlear implants (CIs) for one, two, three, four, and five years to understand how many years of implant use were needed for them to reach a plateau-level performance; (2) to investigate the relation between subjective rating scales and objective measurements (i.e., speech perception tests); (3) to understand the effect of age at implantation on auditory and speech development. METHODS: Eighty-four children with CIs participated in this study. Their auditory performance and speech intelligibility were rated using the Categorical Auditory Performance (CAP) and the Speech Intelligibility Rating (SIR) scales, respectively. The evaluations were made before implantation and six months, one, two, three, four, and five years after implantation. At the fifth year after implantation, monosyllabic-word, easy-sentence, and difficult-sentence perception tests were administered. RESULTS: The median CAP score reached a plateau at category 6 after three years of implant use. The median SIR arrived at the highest level after five years of use. With five years of CI experiences, 86% of the subjects understood conversation without lip-reading, and 58% were fully intelligible to all listeners. The three speech perception tests had a moderate-to-strong correlation with the CAP and SIR scores. The children implanted before the age of three years had significantly better CAP and monosyllabic word perception test scores. CONCLUSIONS: Five years of follow-up are needed for assessing the post-implantation development of communication ability of prelingually deafened children. It is recommended that hearing-impaired children receive cochlear implantation at a younger age to acquire better auditory ability for developing language skills. Constant postoperative aural-verbal rehabilitation and speech and language therapy are most likely required for the patients to reach the highest level on the CAP and SIR scales.

Speech perception and communication ability over the telephone by Mandarin-speaking children with cochlear implants.

OBJECTIVE: (1) To understand speech perception and communication ability through real telephone calls by Mandarin-speaking children with cochlear implants and compare them to live-voice perception, (2) to report the general condition of telephone use of this population, and (3) to investigate the factors that correlate with telephone speech perception performance. METHODS: Fifty-six children with over 4 years of implant use (aged 6.8-13.6 years, mean duration 8.0 years) took three speech perception tests administered using telephone and live voice to examine sentence, monosyllabic-word and Mandarin tone perception. The children also filled out a questionnaire survey investigating everyday telephone use. Wilcoxon signed-rank test was used to compare the scores between live-voice and telephone tests, and Pearson's test to examine the correlation between them. RESULTS: The mean scores were 86.4%, 69.8% and 70.5% respectively for sentence, word and tone recognition over the telephone. The corresponding live-voice mean scores were 94.3%, 84.0% and 70.8%. Wilcoxon signed-rank test showed the sentence and word scores were significantly different between telephone and live voice test, while the tone recognition scores were not, indicating tone perception was less worsened by telephone transmission than words and sentences. Spearman's test showed that chronological age and duration of implant use were weakly correlated with the perception test scores. The questionnaire survey showed 78% of the children could initiate phone calls and 59% could use the telephone 2 years after implantation. CONCLUSION: Implanted children are potentially capable of using the telephone 2 years after implantation, and communication ability over the telephone becomes satisfactory 4 years after implantation.

Predictor of auditory performance in mandarin chinese children with cochlear implants.

OBJECTIVE: The objectives of this investigation were to analyze auditory performance among Mandarin-speaking school-aged children with cochlear implants from their parents' perspective and to derive predictive factors of the performance. STUDY DESIGN: Parental perspective survey of cochlear implant outcome was developed, and factor analysis of auditory performance was performed by analysis of variance. Categorical regression and Pratt measure of relative importance were approached to derive predictive factors of the performance. SETTING: Chung Shan Medical University, School of Speech Language Pathology and Audiology, and 7 major cochlear implant hospitals in Taiwan. PATIENTS: A total of 177 parents of school-aged children with cochlear implants, with a mean age of 11.36 years (range, 6.75-18.75 yr), were included as participants from 7 major cochlear implant centers nationally. INTERVENTION: All children received unilateral multichannel cochlear implants for a 1-year experience. MAIN OUTCOME MEASURES: The CAPR was the measure of auditory performance, and 31 variables from 5 parts of the recipients' information were explored as independent variables. RESULTS: Of all children with implants, 63.8% reached the level of telephone use. Analysis of variance showed that 9 variables correlated significantly with auditory performance (F = 14.04, p < 0.001; multiple R = 0.79, R = 0.63). Categorical regression demonstrated that 5 factors, namely, "no additional disabilities," "oral/aural communication mode at home" and "at school," "educational placement," and "perception of implantation decision" predicted auditory performance. CONCLUSION: Parental perspective survey demonstrated the level of auditory performance among 177 school-aged children with implant. Five factors were found to predict the auditory performance of these children, suggesting the recipient's participation in the environments, oral/aural communication mode, and without additional disabilities significantly contributing auditory performance. The parent's view of cochlear implantation provides not only an important value of children's function in real life but also as another outcome measure.

Lexical effects on spoken word recognition performance among Mandarin-speaking children with normal hearing and cochlear implants.

OBJECTIVE: This investigation aimed to examine the effects of word frequency and lexical neighborhood density on spoken word recognition of monosyllables and disyllables in Mandarin by normal hearing children and children with cochlear implants. The lexical characteristics were incorporated from the Neighborhood Activation Model (NAM), which suggests that words in the mental lexicon are organized into similarity neighborhoods. The difficulty of a listener's task is affected by the frequency of the target word and the density of the lexical neighbors from which that word must be identified. The Monosyllabic Lexical Neighborhood Test and the Disyllabic Lexical Neighborhood Test in Mandarin Chinese (Mandarin LNT and MLNT) were developed to take into account the effects of these linguistic and cognitive demands on speech perception performance. METHODS: Three stages were conducted in this investigation. In the first stage, Mandarin words of monosyllables and disyllables were selected and their lexical properties were calculated from the CHILDES database. Four lexically "easy" and four lexically "hard" word lists in Mandarin LNT as well as two word lists across lexical properties among disyllables were determined based on their relative word frequencies and neighborhood densities. In the second stage, word stimuli were verified by 30 children of the NH group and 36 children from the CI group. In the third stage, the inter-list equivalency and test-retest reliability of word lists across lexical properties were determined, and the correlations of Mandarin LNT and MLNT with other measures and inter-rater reliability were also investigated. RESULTS: Word recognition scores were higher among disyllables than among monosyllables. Lexically "easy" disyllabic words were better recognized than their "hard" counterparts and the monosyllables among two groups of children. However, no lexical effects on word recognition of Mandarin monosyllables were observed for either group. No significant differences were found among word lists in each combination of syllable structure and lexical property. Inter-rater reliability, inter-list equivalency, and test-retest reliability were revealed. The Mandarin LNT and MLNT were found to be highly reliable measures of spoken word recognition (r = 0.84; p < 0.01) with acceptable equivalency between lists (r = 0.638-0.876). CONCLUSION: Lexical effects on Mandarin word recognition were only demonstrated among disyllabic words by NH and the CI children, while Mandarin homophones appearing in monosyllabic words were suggested. Lexical effects on spoken word recognition in Mandarin are not substantially demonstrated as in English, but the Mandarin LNT and MLNT provided reliable information on the spoken word recognition of pediatric CI users in the initial stage after implantation as well as in the rehabilitation progress.

Pediatric cochlear implantation in Taiwan: long-term communication outcomes.

OBJECTIVES/HYPOTHESIS: Cochlear implantation is an established method of auditory rehabilitation for severely and profoundly hearing impaired individuals. Although numerous studies have examined communication outcomes in pediatric cochlear implant (CI) recipients, data concerning the benefits of cochlear implantation in children who speak Mandarin Chinese are lacking. This study examined communication outcomes in 29 Mandarin-speaking children implanted at Chung Gung Memorial Hospital. DESIGN: A prospective between-groups design was used to compare communication outcomes as a function of age at time of implantation. METHODS: Children in the Younger group were implanted before 3 years of age, whereas children in the Older group were implanted after 3 years of age. Outcome measures assessed auditory thresholds, speech perception, speech intelligibility, receptive and expressive language skills, communication barriers, and communication mode. Correlation analysis was used to examine the relationship between communication outcome and age at implantation. RESULTS: Children in the Younger group demonstrated a significant level of difference on Mandarin vowels, consonants, tones, and open-set speech perception compared with the children in the Older group. Between-group differences were also shown on receptive and expressive language skills. But, no significant differences were noted on speech intelligibility or in self-ratings of communication barriers. A larger proportion of children in the Younger group used oral communication and were educated in mainstream classrooms. Communication mode change of the Younger group reached a significant level after cochlear implant. Speech perception performance was negatively correlated with age at implantation as well as chronological age. Mandarin-speaking children can obtain substantial communication benefits from cochlear implantation, with earlier implantation yielding superior results.