Performance of Sequentially Bilateral Cochlear Implanted Children Who Speak Mandarin.

INTRODUCTION: Cochlear implantation is an effective treatment for children with deafness. Although the binaural effect of bilateral cochlear implantation on sound localization and speech perception in noisy environments has been demonstrated, the outcome and performance predictors of the second cochlear implant (CI2) remain uncertain for patients receiving sequential implantation. This study evaluated the hearing performance between the first cochlear implant (CI1), CI2, and bilateral cochlear implants (CI1+2) among children with sequential bilateral cochlear implantation. METHODS: This single-center retrospective study enrolled 14 children and adolescents aged 8-18 years who underwent sequential bilateral cochlear implantation with a mean interimplant interval of 8.2 years. The Mandarin Lexical Neighborhood Test (M-LNT), the Mandarin Hearing in Noise Test (M-HINT), and the Comprehensive Cochlear Implant Questionnaire (CCIQ) scores of participants were evaluated. Mann-Whitney U tests and Spearman correlation analysis were performed to analyze factors associated with CI2 performance. RESULTS: In the 1-year follow-up period after CI2 implantation, although the M-LNT mean score for CI2 was significantly lower than that for CI1, the M-LNT scores for CI2 and CI1+2 improved significantly over time. In a noisy environment, CI1+2 significantly outperformed CI1 in the M-HINT. The M-LNT score for CI2 was significantly associated with preoperative bimodal fitting, residual hearing of the second implanted ear, and CI2 daily-usage time. Specific to CI2, the CCIQ showed improvement 1 year after CI2 implantation. CONCLUSION: CI2 improved the hearing performance and quality of life of recipients with longer interimplant intervals, especially in noisy environments, and its efficacy was associated with preoperative bimodal fitting and regular daily use.

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.

Comparison of Mandarin tone and speech perception between advanced combination encoder and continuous interleaved sampling speech-processing strategies in children.

OBJECTIVE: This study was performed to compare cochlear implant (CI) users' performance in Mandarin speech and tone perception between 2 types of speech-processing strategies-advanced combination encoder (ACE) and continuous interleaved sampling (CIS)-under quiet and noisy conditions. METHODS: This study involved 10 congenitally deaf children (age range, 5.7-15.3 years; mean, 9.2 years) who received the Nucleus 24-channel CI system cochlear device (CI24R; Cochlear Ltd, Lane Cove NSW, Australia). The subjects used ACE since switching on their CI devices. Speech and tone perception tests were administered under quiet and noisy (+5 dB signal-to-noise ratio) conditions with ACE and CIS strategies 20 minutes and 2 weeks apart. RESULTS: Regardless of the strategy used, subjects showed significantly higher scores in speech perception than in tone recognition. Under noisy conditions, subjects had significantly higher tone identification scores with the CIS than the ACE strategy (P = .038). There was no significant difference in speech identification score between the strategies. Subjects showed significant higher tone identification and speech perception scores under quiet than noisy (+5 dB signal-to-noise ratio) conditions. Subjectively, 6 subjects preferred the ACE strategy, and the remaining 4 preferred the CIS strategy. The strategy preference of the subjects was related to speech perception performance rather than tone identification. A significant correlation was observed between tone identification and speech recognition, regardless of whether speech was evaluated by consonants (r = 0.669, P < .001), vowels (r = 0.426, P = .001), or sentences (r = 0.294, P = .023). CONCLUSION: There are only 4 patterns of tone in Mandarin, which is far fewer than the number of speech sounds. However, tone identification is poorer than speech perception. The CIS speech-processing strategy may improve tone identification under noisy conditions. Before improved speech strategies to code acoustic characteristics of tone can be developed, it would be worthwhile to try both CIS and ACE for CI users and to select the most suitable speech-processing strategy according to the subjective preference and objective performance.

The prediction of hearing thresholds with auditory steady-state responses for cochlear implanted children.

OBJECTIVES: The objectives of this study were to investigate the efficacy of auditory steady-state response (ASSR) in predicting cochlear implanted children's actual behavioural thresholds at various frequencies. METHODS: Twenty-two children with cochlear implants (Nucleus 24 devices) participated in this study. Behavioural thresholds and/or ASSR in cochlear implanted children were obtained to determine the predictive accuracy rates and errors by comparing the estimated range of thresholds with the actual behavioural thresholds. RESULTS: Stable ASSR threshold results were obtained in 22 cochlear implanted children. The predictive accuracy rates were the highest and prediction errors were the smallest at 4000 Hz, among the four tested frequencies, using either the Rance 1995 or the Rance 2002 linear regression formulae. The Rance 2002 regression formulae had a higher predictive accuracy and fewer errors than the Rance 1995 regression formulae in predicting the hearing threshold of cochlear implanted patients at all tested frequencies. CONCLUSIONS: Both behavioural thresholds and ASSR thresholds revealed significant improvements after cochlear implantation. ASSR may be used as a tool in predicting hearing thresholds after cochlear implantation in children. The predictive accuracy is best at 4000 Hz with the Rance 2002 linear regression formulae.

Telephone speech perception by Mandarin-speaking cochlear implantees.

OBJECTIVE: To evaluate Mandarin-speaking cochlear implant patients' understanding of telephone speech. DESIGN: Telephone speech was simulated by band-limiting broadband speech stimuli (300-3200 Hz) and adding Gaussian noise (35 dB signal-to-noise ratio). Recognition of multitalker vowels, consonants, voice gender, and Chinese tones was measured for both simulated telephone speech and broadband speech in fifteen Mandarin-speaking cochlear implant patients. RESULTS: Results showed no significant difference in Chinese tone recognition scores between broadband and telephone speech. However, mean recognition scores for vowels, consonants and voice gender were significantly lower with telephone speech. The effect of the limited telephone bandwidth on speech recognition was highly variable among subjects. Some subjects were more sensitive to high-frequency speech cues, resulting in a significant drop in performance with band-limited telephone speech, while other subjects were less sensitive to high-frequency speech cues, resulting in similar performance between broadband and band-limited telephone speech. CONCLUSIONS: These results suggest that the limited bandwidth negatively affects cochlear implant patients' understanding of telephone speech. Because the effect of band-limited speech was highly variable among subjects, the results also suggest that the contribution of high frequency information to speech recognition may vary significantly among cochlear implant patients. For patients who receive little benefit from high-frequency speech cues, speech processor adjustments may be necessary to access the additional cues provided in broadband speech.

Relationships among speech perception, self-rated tinnitus loudness and disability in tinnitus patients with normal pure-tone thresholds of hearing.

Exactly how speech perception and tinnitus perception are related remains unclear. This study investigated how tinnitus alone affects speech perception and the relationship between speech perception, tinnitus loudness, and tinnitus disability. The Mandarin Speech Perception in Noise Test (MSPIN), Tinnitus Loudness Scaling (TLS), and Tinnitus Handicap Inventory (THI) were utilized to assess 20 tinnitus patients with normal hearing. The tinnitus group had a significantly lower MSPIN score than the control group (p < 0.01). TLS and THI scores were strongly correlated (r(2): 0.534 approximately 0.627, p < 0.05). Correlations between MSPIN and TLS or THI scores were not significant. Tinnitus loudness correlated well with tinnitus-related disability. Neither tinnitus loudness nor disability was strongly correlated with speech perception. In noisy environments, tinnitus sufferers had significantly poorer ability to recognize speech than control subjects.

Antrodia camphorata polysaccharides exhibit anti-hepatitis B virus effects.

Polysaccharides were extracted from fruiting bodies and cultured mycelia from five Antrodia camphorata strains. Polysaccharide profiles of the five strains, as determined by high-performance anion-exchange chromatography, showed varying yields and composition of neutral sugars. A. camphorata fruiting bodies also had different polysaccharide patterns compared to the cultured mycelium. Analysis of 26-day-old mycelia showed that the neutral sugars galactose, glucose, mannose, and galactosamine were predominant. All mycelia polysaccharide preparations exhibited anti-hepatitis B virus activity. Polysaccharides from strain B86 at a concentration of 50 microg ml(-1) showed the highest level of anti-hepatitis B surface antigen effect, which was higher than alpha-interferon at a dosage of 1000 U ml(-1). Only strains B86 and 35398 had substantial anti-hepatitis B e antigen activities. None of the polysaccharides exhibited cytotoxic effects.