The Advances in Hearing Rehabilitation and Cochlear Implants in China

Impact of Cochlear Implantation on Quality of Life in Chinese Americans

OBJECTIVES

To investigate the quality of life (QOL) of adult Mandarin-speaking Chinese Americans after cochlear implantation (CI) using the cross-culturally adapted Chinese Cochlear Implant Quality of Life-10 (CIQOL-10) Global.

STUDY DESIGN

Cross-sectional.

SETTING

Tertiary care neurotology practice in New York City.

PATIENTS

Thirty adult Mandarin-speaking Chinese Americans (22.8-89.4 yr, mean 48.9 yr) with prelingual (12) or postlingual (18) deafness who underwent CI between 1995 and 2020. All patients were at least 1 year from CI activation.

INTERVENTION

CI.

MAIN OUTCOMES MEASURES

Chinese CIQOL-10 Global score.

RESULTS

There were no detectable differences in mean Chinese CIQOL-10 Global scores between the prelingual (mean 51.9, SD 11.0) and postlingual (mean 44.0, SD 16.4) cohorts (p = 0.1; 95% CI, -2.3 to 18.1; Hedges' g = 0.5). Comparison of the overall cohort (mean 47.1, SD 14.8) with previously published CIQOL-10 Global scores of English-speaking American CI users (mean 51.5, SD 10.4) demonstrated a significant difference (p = 0.02; 95% CI, 0.4-8.4; Hedges' g = 0.4). For the overall cohort, multivariable analysis demonstrated that combined household income (p = 0.007, β = 7.4; 95% CI, 0.7-14.0) was positively associated with Chinese CIQOL-10 Global scores.

CONCLUSIONS

This study is the first to evaluate QOL after CI in Mandarin-speaking Chinese American adults. The CIQOL-10 Global scores of Mandarin-speaking Chinese Americans CI users are significantly worse than those of English-speaking American CI users. Combined household income may be positively associated with QOL in the Mandarin-speaking Chinese American CI population. More resources are needed to assess outcomes and support rehabilitation in this population.

A 10-year in-depth follow-up of post-lingual hearing loss patients with Chinese domestic cochlear implants

BACKGROUND

Follow-up of cochlear implant effectiveness is mainly focused on 3 years postoperatively, and studies with more than 5 years of observation are rare, especially for local Chinese brands.

OBJECTIVES

Nurotron (Chinese domestic cochlear implant brand) CI recipients who participated in the clinical trial in 2009 were followed-up for 10 years prospectively, providing data to guide doctors and patients.

MATERIAL AND METHODS

From December 2009 to April 2010, 57 subjects underwent Nurotron Venus CI surgery at multiple-centers, and were continued to be followed up and assessed at 1, 2, 3, 4, 5, and 10 years after switch on.

RESULTS

All recipients were successfully implanted with CIs with no difficulty in subsequent use with one reported case of re-implantation at 9 years after implantation. The aided hearing thresholds were significantly improved at one month after switch on (p < 0.0001) and remained stable afterwards for 10 years. Speech recognition scores were significantly higher than pre-operative results (p < 0.05) and continued to improve till 3 years after switch on. At 10 years post-operation, most subjects had improved QOL scores in most sub-items.

CONCLUSIONS AND SIGNIFICANCE

Nurotron Venus CI System provides long-term, stable results in hearing speech assistance capabilities and can improve the quality of life of CI recipients.

List Equivalency and Critical Differences of a Mandarin Bamford-Kowal-Bench Sentence in Babble Noise Test for Adults and Preschool Children With Normal Hearing

PURPOSE

The purpose of this study was to determine the speech recognition equivalence of Mandarin Bamford-Kowal-Bench (BKB) sentence lists with adults and children with normal hearing.

METHOD

A total of 32 lists, each of nine sentences, were compiled from a corpus of BKB-like sentences with paired babble in Mandarin. Interlist equivalence, critical differences, and sensitivity of performance to signal-to-noise ratio (SNR) were examined. Experiment 1 included 64 native Mandarin-speaking adults with normal hearing. Experiment 2 included 54 native Mandarin-speaking children with normal hearing aged 4-6 years.

RESULTS

Among the 32 sentence lists, 28 lists were confirmed to be equivalent in adults, with a mean SNR required for 50% correct (SNR50) of -5.9 ± 0.1 dB, a mean slope of 22.3%/dB ± 1.5%/dB, and a grand 95% critical difference subsequently calculated as 27.2% for score. From the 28 equivalent lists, 27 lists were selected and observed to be equivalent in children, with a mean SNR50 threshold of -2.0 ± 0.2 dB, a mean slope of 15.8%/dB ± 1.1%/dB, and a grand 95% critical difference of 24.6% for score.

CONCLUSIONS

The Mandarin BKB sentences in babble noise test offers an opportunity for clinicians and researchers to assess speech understanding in adults and preschool children in an efficient manner. For comparisons of performance in different test conditions, 28 equivalent lists are available for adults and 27 equivalent lists for preschool children. The 95% critical difference values can be used for total percentage correct or SNR for 50% performance. Future work will examine the clinical utility for school-age children and children who are deaf and hard of hearing.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24400066.

Tone perception development in Mandarin-speaking children with cochlear implants

OBJECTIVE

The purpose of this study was to examine the longer-term effects of cochlear implant (CI) use on tone perception by evaluating improvement in Mandarin tone recognition in children with CIs 2 and 3 years post CI activation, and to explore the effects of implant age, chronological age and duration of CI use on the development of tone perception.

METHODS

Tone perception was assessed in 29 bilateral profound hearing impaired children (mean chronological age = 4.6 years, SD = 0.7 years) with unilateral CIs at 24 and 36 months after CI activation using the tone perception subtest in the Mandarin Early Speech Perception (MESP-T) test.

RESULTS

Children's tone recognition for tone pairs and individual tones improved significantly between 2 and 3 years post CI use, showing an increase in average tone recognition score from 73.2% to 81.8%, which was significantly higher than chance level (i.e. 50%). There was no significant correlation between tone recognition ability and either implant age or chronological age at two evaluation points. Further analysis revealed that the tone recognition score for tone pair 2-3 was significantly lower than that for other tone pairs except for tone pair 2-4.

CONCLUSIONS

Longer CI experience can significantly improve tone recognition ability in CI children between 2 and 3 years post CI activation.

Reading Comprehension of Chinese-Speaking Children With Hearing Loss: The Roles of Metalinguistic Awareness and Vocabulary Knowledge

PURPOSE

This study aims to explore the contributions of phonological awareness (PA) and morphological awareness (MA) to the reading comprehension skills of Chinese-speaking children with hearing loss (HL) and examine the possible mediation effect of vocabulary knowledge on the relationships of PA and MA with their reading comprehension.

METHOD

The participants were 28 Chinese-speaking children with HL, who were followed from Grade 1 through Grade 2. They were administered a series of tests that measured their PA and MA at the beginning of Grade 1, vocabulary knowledge at the end of Grade 1, and reading comprehension at the end of Grade 2.

RESULTS

MA significantly accounted for additional variance in reading comprehension beyond the effect of PA but not vice versa. Both PA and MA contributed uniquely to vocabulary knowledge, which completely mediated the relationships of PA and MA with reading comprehension.

CONCLUSIONS

PA and MA are both essential to the development of vocabulary knowledge and reading comprehension in Chinese-speaking children with HL; however, MA seems to be more important than PA in their reading comprehension. PA and MA significantly affect children's reading comprehension through their influence on vocabulary knowledge. This study has replicated previous evidence on the importance of PA, MA, and vocabulary knowledge in the reading comprehension of children with typical hearing, and has extended its significance to children with HL. In addition, the findings have the potential to inform educational practitioners regarding the importance of teaching essential reading skills to Chinese-speaking children with HL.

The 100 Most-Cited Manuscripts in Hearing Implants: A Bibliometrics Analysis

The aim of the study was to characterise the most frequently cited articles on the topic of hearing implants. A systematic search was carried out using the Thomson Reuters Web of Science Core Collection database. Eligibility criteria restricted the results to primary studies and reviews published from 1970 to 2022 in English dealing primarily with hearing implants. Data including the authors, year of publication, journal, country of origin, number of citations and average number of citations per year were extracted, as well as the impact factors and five-year impact factor of journals publishing the articles. The top 100 papers were published across 23 journals and were cited 23,139 times. The most-cited and influential article describes the first use of the continuous interleaved sampling (CIS) strategy utilised in all modern cochlear implants. More than half of the studies on the list were produced by authors from the United States, and the Ear and Hearing journal had both the greatest number of articles and the greatest number of total citations. To conclude, this research serves as a guide to the most influential articles on the topic of hearing implants, although bibliometric analyses mainly focus on citations. The most-cited article was an influential description of CIS.

Tone evaluation of Ling sound test in Mandarin tone version

BACKGROUND

The Ling sound test cannot provide the test of Chinese tone for preschool children with hearing aid and cochlear implants.

OBJECTIVE

The paper tries to design a new tone test method composed of the Ling sound test and four Chinese tones to evaluate the hearing level of Chinese hearing-impaired children.

METHODS

The tone identification rates of 20 cochlear implant children were statistically analyzed to verify the validity of the Ling sound test in the Chinese tone version. In addition, this paper analyzed the pronunciation characteristics of the Ling sound test in the Chongqing-accented Mandarin version of 20 subjects.

RESULTS

The identification rate of Ling six sounds was more than 97.0%, the identification rate of tone was more than 81.0%, and the identification rate of vowels was 83.1%, which was higher than that of consonants 79.0%. The Ling sound test n the Chongqing-accented Mandarin version has a narrower frequency range.

CONCLUSION

The results verify the effectiveness and feasibility of the Ling sound test in the Chinese tone version in the assessment of frequency range and tone identification for cochlear implant users.

Pitch perception with the temporal limits encoder for cochlear implants

The temporal-limits-encoder (TLE) strategy has been proposed to enhance the representation of temporal fine structure (TFS) in cochlear implants (CIs), which is vital for many aspects of sound perception but is typically discarded by most modern CI strategies. TLE works by computing an envelope modulator that is within the temporal pitch limits of CI electric hearing. This paper examines the TFS information encoded by TLE and evaluates the salience and usefulness of this information in CI users. Two experiments were conducted to compare pitch perception performance of TLE versus the widely-used Advanced Combinational Encoder (ACE) strategy. Experiment 1 investigated whether TLE processing improved pitch discrimination compared to ACE. Experiment 2 parametrically examined the effect of changing the lower frequency limit of the TLE modulator on pitch ranking. In both experiments, F0 difference limens were measured with synthetic harmonic complex tones using an adaptive procedure. Signal analysis of the outputs of TLE and ACE strategies showed that TLE introduces important temporal pitch cues that are not available with ACE. Results showed an improvement in pitch discrimination with TLE when the acoustic input had a lower F0 frequency. No significant effect of lower frequency limit was observed for pitch ranking, though a lower limit did tend to provide better outcomes. These results suggest that the envelope modulation introduced by TLE can improve pitch perception for CI listeners.

Differential weighting of temporal envelope cues from the low-frequency region for Mandarin sentence recognition in noise

BACKGROUND

Temporal envelope cues are conveyed by cochlear implants (CIs) to hearing loss patients to restore hearing. Although CIs could enable users to communicate in clear listening environments, noisy environments still pose a problem. To improve speech-processing strategies used in Chinese CIs, we explored the relative contributions made by the temporal envelope in various frequency regions, as relevant to Mandarin sentence recognition in noise.

METHODS

Original speech material from the Mandarin version of the Hearing in Noise Test (MHINT) was mixed with speech-shaped noise (SSN), sinusoidally amplitude-modulated speech-shaped noise (SAM SSN), and sinusoidally amplitude-modulated (SAM) white noise (4 Hz) at a + 5 dB signal-to-noise ratio, respectively. Envelope information of the noise-corrupted speech material was extracted from 30 contiguous bands that were allocated to five frequency regions. The intelligibility of the noise-corrupted speech material (temporal cues from one or two regions were removed) was measured to estimate the relative weights of temporal envelope cues from the five frequency regions.

RESULTS

In SSN, the mean weights of Regions 1-5 were 0.34, 0.19, 0.20, 0.16, and 0.11, respectively; in SAM SSN, the mean weights of Regions 1-5 were 0.34, 0.17, 0.24, 0.14, and 0.11, respectively; and in SAM white noise, the mean weights of Regions 1-5 were 0.46, 0.24, 0.22, 0.06, and 0.02, respectively.

CONCLUSIONS

The results suggest that the temporal envelope in the low-frequency region transmits the greatest amount of information in terms of Mandarin sentence recognition for three types of noise, which differed from the perception strategy employed in clear listening environments.

Vocabulary Growth in Mandarin-Speaking Children With Bilateral Cochlear Implants, Bimodal Stimulation, or Unilateral Cochlear Implants During the First Year After Activation

PURPOSE

The purpose of this study was to evaluate vocabulary development in Mandarin-speaking children with bilateral cochlear implants (CIs), bimodal stimulation (CI plus hearing aids [HAs]), or unilateral CIs during the first year after CI activation.

METHOD

Participants included 23 children with simultaneous bilateral CIs, 23 children with bimodal stimulation, and 15 children with unilateral CIs. They all received CIs before 30 months of age. Parents were asked to endorse words that their child could understand only or understand and say using the Early Vocabulary Inventory for Mandarin Chinese at the day of CI activation and 1, 3, 6, 9, and 12 months after CI activation. Receptive and expressive vocabulary sizes were computed.

RESULTS

Growth curve analysis revealed that children with simultaneous bilateral CIs demonstrated faster growth of receptive vocabulary than those with bimodal stimulation, followed by those with unilateral CIs. Moreover, children with simultaneous bilateral CIs reached the 100-word mark for receptive vocabulary earlier than children with bimodal stimulation, followed by those with unilateral CIs. There were no significant differences among the three groups in expressive vocabulary.

CONCLUSIONS

Bilateral CIs have an advantage over bimodal stimulation in early receptive vocabulary development in Mandarin, a tone language. HA usage is still recommended for those who receive one CI.

Audiologist’s Perspective in Auditory Rehabilitation: Implications for Ethical Conduct and Decision-Making in Portugal

Ethical standards in audiology have been continuously improved and discussed, leading to the elaboration of specific regulatory guidelines for the profession. However, in the field of auditory rehabilitation, audiologists are still faced with circumstances that question their ethical principles, usually associated with the support of the hearing aids industry. The study explores the decision-making process and ethical concerns in auditory rehabilitation as they relate to the practice of audiology in Portugal. An online questionnaire constructed by the authors was used and sent to the email addresses of a list of audiologists, registered with the Portuguese Association of Audiologists. The questionnaire was answered by 93 audiologists with clinical experience in auditory rehabilitation for more than one year. The collected data demonstrated that audiometric results and clinical experience are the most important factors for decision-making in auditory rehabilitation practice. Moreover, incentives from the employers or manufacturers were identified as the main cause of ethical dilemmas. This study highlights the ethical concerns regarding the clinical practice of auditory rehabilitation in Portugal, revealing that the decision-making process is complex and, specifically in this field, the current practice may not be adequate for effective compliance with professional ethical standards.

Change in Health-Related Quality of Life in Cochlear Implant Recipients in China

Objective

The objective is to assess the benefit of cochlear implants in health-related quality of life among postlingually deaf adults in China.

Methods

Seventy-one postlingually deaf adult cochlear implant users in one cochlear implant center in China participated in this study. The HUI3 questionnaire as a measurement evaluated their quality of life. A cross-sectional analysis was conducted.

Results

Cochlear implant had made statistically significant improvements in quality of life among postlingually deaf adults. The HUI3 scores were significantly better in four attributes (hearing, speech, emotion, and pain) after a cochlear implant. A positive correlation between change in hearing and improvement in emotion was significant. The change in pain and improvement in emotion also had a positive correlation. The duration of HA and CI use had no impact on the gain in HUI3 scores, and the baseline of hearing and emotion state had an influence on HUI3 gain.

Conclusion

This study found cochlear implant users had a greatly improved hearing, speech, emotion, and pain, which made statistically significant improvement in quality of life among postlingually deaf adults. There was a statistically significant association between the change of emotion state and improvement in hearing level. We also found a statistically significant correlation between the reduction of feeling in pain and improvement in emotion. The change of quality of life seemed to be influenced by the primary state of emotion and hearing. We believe the measurement HUI3 is suitable for these patients in China.

A Review of Speech Perception of Mandarin-Speaking Children With Cochlear Implantation

Objective: This paper reviewed the literature on the development of and factors affecting speech perception of Mandarin-speaking children with cochlear implantation (CI). We also summarized speech outcome measures in standard Mandarin for evaluating auditory and speech perception of children with CI.

Method: A comprehensive search of Google Scholar and PubMed was conducted from March to June 2021. Search terms used were speech perception/lexical tone recognition/auditory perception AND cochlear implant AND Mandarin/Chinese.

Conclusion: Unilateral CI recipients demonstrated continuous improvements in auditory and speech perception for several years post-activation. Younger age at implantation and longer duration of CI use contribute to better speech perception. Having undergone a hearing aid trial before implantation and having caregivers whose educational level is higher may lead to better performance. While the findings that support the use of CI to improve speech perception continue to grow, much research is needed to validate the use of unilateral and bilateral implantation. Evidence to date, however, revealed bimodal benefits over CI-only conditions in lexical tone recognition and sentence perception in noise. Due to scarcity of research, conclusions on the benefits of bilateral CIs compared to unilateral CI or bimodal CI use cannot be drawn. Therefore, future research on bimodal and bilateral CIs is needed to guide evidence-based clinical practice.

Long-Term Release of Dexamethasone With a Polycaprolactone-Coated Electrode Alleviates Fibrosis in Cochlear Implantation

Cochlear implantation (CI) is the major treatment for severe sensorineural hearing loss. However, the fibrotic tissue forming around the electrodes reduces the treatment effectiveness of CI. Dexamethasone (DEX) is usually applied routinely in perioperative treatment of cochlear implantation (CI), but its diffusion in the inner ear after systemic administration is limited. In the present study, an electrode coated with polycaprolactone (PCL) loaded with dexamethasone was developed with a simple preparation process to maintain the stability of the electrode itself. The DEX-loaded PCL coating has good biocompatibility and does not change the smoothness, flexibility, or compliance of the implant electrode. Stable and effective DEX concentrations were maintained for more than 9 months. Compared with the pristine electrode, decreasing intracochlear fibrosis, protection of hair cells and spiral ganglion cells, and better residual hearing were observed 5 weeks after PCL-DEX electrode implantation. The PCL-DEX electrode has great potential in preventing hearing loss and fibrosis by regulating macrophages and inhibiting the expression of the fibrosis-related factors IL-1β, TNF-α, IL-4, and TGF-β1. In conclusion, the PCL-DEX electrode coating shows promising application in CI surgery.

Exosomes derived from cochlear spiral ganglion progenitor cells prevent cochlea damage from ischemia-reperfusion injury via inhibiting the inflammatory process

Ischemia-reperfusion injury (I/R)-induced inflammatory process can mediate cochlea damage-related hearing loss; whether cochlear spiral ganglion progenitor cell-derived exosomes (CSGPC-exos) play a protective role by carrying functional microRNAs into recipient cells is unknown. Different doses of CSGPC-exos (0.1 μg/μl, 0.2 μg/μl, 0.5 μg/μl, 1.0 μg/μl) were administrated into the cochleae of the I/R group induced with 30-min occlusion of the bilateral vertebral arteries and sham surgery group. The speech-evoked auditory brainstem response (ABR) test was utilized to estimate the auditory threshold shift. The relative expression of proinflammatory cytokines was detected with RT-PCR and Western blot, while parvalbumin and caspase-3 expression were detected by immunofluorescence staining in the cochleae. The relative expression of microRNAs (miR-21-5p, miR-26a-5p, and miR-181a-5p) was detected in the cochleae. I/R significantly up-regulated ABR threshold shift and promoted hair cell apoptosis indicated by parvalbumin and caspase-3 staining, while CSGPC-exos (0.5 μg/μl, 1.0 μg/μl) could diminish such damages with downregulated proinflammatory factors (IL-6, IL-1β, TNF-α, and Cox-2) and upregulated anti-inflammatory miRNAs (miR-21-5p, miR-26a-5p, and miR-181a-5p) expression in the cochleae. CSGPC-exos could protect cochleae damage from I/R, probably via inhibiting the inflammatory process.

Speech production in Mandarin-speaking children with cochlear implants: a systematic review

OBJECTIVE

This study aimed to systematically review and critically appraise the literature describing the phonetic characteristics and accuracy of the consonants, vowels and tones produced by Mandarin-speaking children with cochlear implants (CIs).

DESIGN

The protocol in this review was designed in conformity with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. EBSCOhost, PubMed, Scopus, PsycINFO, ProQuest Central databases were searched for relevant articles which met the inclusion criteria.

STUDY SAMPLE

A total of 18 journal papers were included in this review.

RESULTS

The results revealed that Mandarin-speaking children with CIs perform consistently more poorly in their production of consonants, in particular on fricatives, have a smaller and less well-defined vowel space, and exhibit greater difficulties in tone realisation, notably T2 and T3, when compared to their normal-hearing (NH) peers. The results from acoustic and accuracy analyses are negatively correlated with CI implantation age, but largely positively correlated with hearing age.

CONCLUSIONS

Findings of this review highlight the factors that influence consonant, vowel and tone production in Mandarin-speaking children with CIs, thereby providing critical information for clinicians and researchers working with this population.

Hearing Protection Outcomes of Analog Electrode Arrays Coated with Different Drug-Eluting Polymer Films Implanted into Guinea Pig Cochleae

Objective

To investigate the hearing protection outcomes of different drug-eluting analog electrode arrays implanted into guinea pig cochleae.

Methods

Sixty guinea pigs were randomly divided into a negative control group and five experimental groups implanted separately with blank (drug carrier), dexamethasone (DXM), aracytine (Ara-C), Ara-C+DXM, and nicotinamide adenine dinucleotide (NAD+) eluting analog electrode arrays. Micro CT was used to supervise the surgical procedure. Auditory brainstem response (ABR) thresholds of the guinea pigs were measured and analyzed.

Results and Conclusions

Compared with the negative control, all other groups showed a significant increase in ABR threshold (p<0.001) after surgery. Among them, there was no obvious difference between the blank (0 vs 90 days: 59.70±10.57 vs 64.60±9.47 dB SPL) and the NAD+ group (0 vs 90 days: 59.90±9.87 vs 64.70±8.65 dB SPL). On the other hand, the ABR thresholds in the DXM (0 days: 58.10±10.73 dB SPL; 90 days: 51.70±9.07 dB SPL) and the Ara-C group (0 days: 59.00±10.05 dB SPL; 90 days: 51.60±8.48 dB SPL) decreased significantly compared with the former two groups (p<0.001). However, the Ara-C+DXM group showed no further benefit (p>0.05). In addition, a significantly higher survival rate of spiral ganglion neurons in cochleae was observed in the Ara-C and/or DXM groups.

Factors influencing rehabilitation effect in prelingually deafened late implanted cochlear implant users, and the construction of a nomogram

OBJECTIVES

Our study aimed to identify potential factors that may influence rehabilitation outcomes in late-implanted adolescents and adults with prelingual deafness and to construct a user-friendly nomogram.

DESIGN

This cross-sectional study included 120 subjects under 30 years of age who had received cochlear implantation at a single medical center. The Categories of Auditory Performance (CAP) scale was used to evaluate the rehabilitation outcomes. A nomogram was constructed by using the R and EmpowerStats software.

RESULTS

Univariate analysis indicated higher rates of auditory performance improvement in younger aged subjects. Residual hearing and regular implant use were more frequently seen among subjects with auditory performance improvement. Multivariate analysis identified residual hearing (Hazard Ratio, 6.11; 95% Confidence Interval, 1.83-20.41; P<0.01), age group (Hazard Ratio, 0.31; 95% Confidence Interval, 0.14-0.83; P=0.02) and regular CI use (Hazard Ratio, 7.79; 95% Confidence Interval, 2.50-24.20; P<0.01) as independent predictors for auditory performance improvement. The nomogram's predictive performance was satisfactory as shown by the calibration curve and Receiver operating characteristic (ROC) curve.

CONCLUSIONS

Factors such as residual hearing, younger age, and regular CI use are associated with auditory performance improvement in this cochlear implant user population. The nomogram model also demonstrates a satisfactory predictive performance.

Segregation of competing speech in adults and children with normal hearing and in children with cochlear implants

Children with normal hearing (CNH) have greater difficulty segregating competing speech than do adults with normal hearing (ANH). Children with cochlear implants (CCI) have greater difficulty segregating competing speech than do CNH. In the present study, speech reception thresholds (SRTs) in competing speech were measured in Chinese Mandarin-speaking ANH, CNH, and CCIs. Target sentences were produced by a male Mandarin-speaking talker. Maskers were time-forward or -reversed sentences produced by a native Mandarin-speaking male (different from the target) or female or a non-native English-speaking male. The SRTs were lowest (best) for the ANH group, followed by the CNH and CCI groups. The masking release (MR) was comparable between the ANH and CNH group, but much poorer in the CCI group. The temporal properties differed between the native and non-native maskers and between forward and reversed speech. The temporal properties of the maskers were significantly associated with the SRTs for the CCI and CNH groups but not for the ANH group. Whereas the temporal properties of the maskers were significantly associated with the MR for all three groups, the association was stronger for the CCI and CNH groups than for the ANH group.

Manufacturable 32-Channel Cochlear Electrode Array and Preliminary Assessment of Its Feasibility for Clinical Use

(1) Background: In this study, we introduce a manufacturable 32-channel cochlear electrode array. In contrast to conventional cochlear electrode arrays manufactured by manual processes that consist of electrode-wire welding, the placement of each electrode, and silicone molding over wired structures, the proposed cochlear electrode array is manufactured by semi-automated laser micro-structuring and a mass-produced layer-by-layer silicone deposition scheme similar to the semiconductor fabrication process. (2) Methods: The proposed 32-channel electrode array has 32 electrode contacts with a length of 24 mm and 0.75 mm spacing between contacts. The width of the electrode array is 0.45 mm at its apex and 0.8 mm at its base, and it has a three-layered arrangement consisting of a 32-channel electrode layer and two 16-lead wire layers. To assess its feasibility, we conducted an electrochemical evaluation, stiffness measurements, and insertion force measurements. (3) Results: The electrochemical impedance and charge storage capacity are 3.11 ± 0.89 kOhm at 1 kHz and 5.09 mC/cm2, respectively. The V/H ratio, which indicates how large the vertical stiffness is compared to the horizontal stiffness, is 1.26. The insertion force is 17.4 mN at 8 mm from the round window, and the maximum extraction force is 61.4 mN. (4) Conclusions: The results of the preliminary feasibility assessment of the proposed 32-channel cochlear electrode array are presented. After further assessments are performed, a 32-channel cochlear implant system consisting of the proposed 32-channel electrode array, 32-channel neural stimulation and recording IC, titanium-based hermetic package, and sound processor with wireless power and signal transmission coil will be completed.

Genetic testing involving 100 common mutations for antenatal diagnosis of hereditary hearing loss in Chongqing, China

ABSTRACT

To understand the possible carrier status of genes associated with hereditary hearing loss (HHL) in the general population among local residents and to give genetic counseling for pregnant women.A total of 3541 subjects were recruited. We used multiplex PCR technology combined with next-generation sequencing technology to detect 100 hotspot mutations in 18 common deafness-related genes. The homozygous mutation screening results were verified using Sanger sequencing.Of the 3541 participants, 37 alleles of 8 deafness genes were detected. A total of 145 (4.09%) were found to be GJB2 gene mutation carriers, and the hotspot mutation was c.235delC (1.54%). Twenty three (0.65%) were found to be GJB3 gene mutation carriers. A total of 132 (3.37%) were found to be SLC26A4 gene mutation carriers, and the hotspot mutation was c.919-2A > G (0.49%). Forty four (1.24%) were found to be mitochondrial DNA mutation carriers. Sanger sequencing results verified that 2 cases were homozygous for the c.235delC mutation and that 1 case was homozygous for the c.754T > C mutation.Genetic testing for pregnant women and their partners allows early identification of the molecular etiology of hearing loss (HL). On the one hand, it could give genetic counseling for pregnant women, such as early diagnosis of delayed deafness and drug-susceptible deafness. On the other hand, it could be used to assess hearing conditions during pregnancy, leading to prevention and timely intervention for newborns.

Objective electroencephalography-based assessment for auditory rehabilitation of pediatric cochlear implant users

The cochlear implant (CI) has an effective habilitation modality for hearing-impaired children by promoting sound perception, vocalization, and language ability. However, the major challenge that remained was the lack of assessment standards for pediatric CI users, especially prelingually deaf children, to evaluate hearing rehabilitation effectiveness. In the present study, we conducted an oddball paradigm with stimuli varying in pure-tone, syllable, and tonal sounds. After implantation, we utilized cortical auditory evoked potential (CAEP) and mismatch negativity (MMN) to obtain time-domain analysis; meanwhile, the source localization was investigated to obtain spatial accuracy of the plasticity in the auditory cortex. P1 started to emerge at the third month after implantation, but its peak level was not significant until the sixth month. The temporal lobe was activated between the third and sixth months after implantation. The MMN waveform was basically normal approximately after 12 months. These results suggest that the auditory system goes through a critical period of rapid development between three and six months and enters a maturation period after 12 months. This work indicates that CAEPs are more suitable for assessing the early auditory system reconstruction, while MMN performs better in evaluating the advanced auditory function. Furthermore, source localization has proven to be an efficient tool in exploring auditory cortex plasticity, especially for pediatric CI users.

Bimodal Benefits Revealed by Categorical Perception of Lexical Tones in Mandarin-Speaking Kindergarteners With a Cochlear Implant and a Contralateral Hearing Aid

Purpose Pitch reception poses challenges for individuals with cochlear implants (CIs), and adding a hearing aid (HA) in the nonimplanted ear is potentially beneficial. The current study used fine-scale synthetic speech stimuli to investigate the bimodal benefit for lexical tone categorization in Mandarin-speaking kindergarteners using a CI and an HA in opposite ears. Method The data were collected from 16 participants who were required to complete two classical tasks for speech categorical perception (CP) with CI + HA device condition and CI alone condition. Linear mixed-effects models were constructed to evaluate the identification and discrimination scores across different device conditions. Results The bimodal kindergarteners showed CP for the continuum varying from Mandarin Tone 1 and Tone 2. Moreover, the additional acoustic information from the contralateral HA contributes to improved lexical tone categorization, with a steeper slope, a higher discrimination score of between-category stimuli pair, and an improved peakedness score (i.e., an increased benefit magnitude for discriminations of between-category over within-category pairs) for the CI + HA condition than the CI alone condition. The bimodal kindergarteners with better residual hearing thresholds at 250 Hz level in the nonimplanted ear could perceive lexical tones more categorically. Conclusion The enhanced CP results with bimodal listening provide clear evidence for the clinical practice to fit a contralateral HA in the nonimplanted ear in kindergarteners with unilateral CIs with direct benefits from the low-frequency acoustic hearing.

Estimated Cost-effectiveness of Newborn Screening for Congenital Cytomegalovirus Infection in China Using a Markov Model

IMPORTANCE

Congenital cytomegalovirus infection (cCMVi) is one of the most common infections associated with childhood hearing loss. Prevention and mitigation of cCMVi-related hearing loss will require an increase in newborn screening, which is not yet available in China.

OBJECTIVE

To estimate the cost-effectiveness of newborn screening strategies for cCMVi from the perspective of the Chinese health care system.

DESIGN, SETTING, AND PARTICIPANTS

A decision tree for a simulated cohort population of 15 000 000 live births was developed to compare the costs and health effects of 3 mutually exclusive interventions: (1) no screening, (2) targeted screening using CMV polymerase chain reaction assay for newborns who fail a universal hearing screening, and (3) universal screening for CMV among all newborns. Markov diagrams were used to evaluate the lifetime horizon (76 years).

MAIN OUTCOMES AND MEASURES

Cost, hearing-related health outcomes, and incremental cost-effectiveness ratios (ICERs) were estimated based on a direct medical costs perspective. Costs and ICERs were reported in 2018 US dollars.

RESULTS

Incidence of cCMVi among newborns was reported to be approximately 0.7% in China. Targeted screening was less costly but also less effective than universal screening, identifying 41% of cases needing antiviral treatment and preventing nearly half of less severe or profound hearing loss. To avoid 1 CMV-related severe or profound hearing loss, 13 and 16 newborns need to be treated by targeted and universal screening, respectively. The ICERs of targeted and universal screening vs no screening were $79 and $2087 per quality-adjusted life-year gained, respectively, at the discounted rate of 3.5%. Both screening options were cost-effective for the Chinese health care system based on the willingness-to-pay threshold of 3 × gross domestic product per capita. The sensitivity analysis showed that the prevalence of cCMVi, as well as diagnosis and treatment costs, were key factors that may be associated with decision-making.

CONCLUSIONS AND RELEVANCE

To achieve cost-effectiveness and best health outcomes, universal screening could be considered for the Chinese population. While the results are specific to China, the model may easily be adapted for other countries.

Exposure to Chinese famine in early life and the risk of sensory impairment in adulthood

BACKGROUND

Studies have shown that malnutrition in early life has a negative effect on midlife cognitive functions. Little is known, however, about the relationship between early-life malnutrition and visual, hearing or dual sensory impairments in adulthood. This study aims to investigate the association between exposure to the 1959-1961 Chinese famine in early life and sensory impairments in adulthood.

METHODS

A total of 6347 adults born between 1952 and 1964 surveyed in the 2015 China Health and Retirement Longitudinal Study were included in this study. The presence of sensory impairments was identified by self-reported assessment of visual and hearing functions. The associations between multi-stage early-life famine exposure and sensory functions were estimated using the multiple generalised linear model.

RESULTS

Compared with the unexposed group, respondents exposed to famine in the fetal period and late childhood had a significantly higher risk of hearing impairment (OR 1.54, 95% CI 1.06 to 2.24; OR 1.75, 95% CI 1.23 to 2.50) and dual sensory impairments (OR 1.45, 95% CI 1.00 to 2.11; OR 1.55, 95% CI 1.09 to 2.21), respectively. Furthermore, in severely famine-affected areas, the early, mid and late childhood-exposed groups were more likely to have hearing and dual sensory impairments than the unexposed group. Those associations were not observed in less famine-affected areas. However, no significant association was found between famine exposure and visual impairment in early-life famine-exposed group.

CONCLUSION

Exposure to Chinese famine in the fetal period and late childhood was linked to hearing and dual sensory impairments in adulthood.

A Cross-Language Comparison of Sentence Recognition Using American English and Mandarin Chinese HINT and AzBio Sentences

OBJECTIVES

The aim of this study was to perform a cross-language comparison of two commonly used sentence-recognition materials (i.e., Hearing in Noise Test [HINT] and AzBio) in American English (AE) and Mandarin Chinese (MC).

DESIGNS

Sixty normal-hearing, native English-speaking and 60 normal-hearing, native Chinese-speaking young adults were recruited to participate in three experiments. In each experiment, the subjects were tested in their native language. In experiments I and II, noise and tone vocoders were used to process the HINT and AzBio sentences, respectively. The number of channels varied from 1 to 9, with an envelope cutoff frequency of 160 Hz. In experiment III, the AE AzBio and the MC HINT sentences were tested in speech-shaped noise at various signal to noise ratios (i.e., -20, -15, -10, -5, and 0 dB). The performance-intensity functions of sentence recognition using the two sets of sentence materials were compared.

RESULTS

Results of experiments I and II using vocoder processing indicated that the AE and MC versions of HINT and AzBio sentences differed in level of difficulty. The AE version yielded higher recognition performance than the MC version for both HINT and AzBio sentences. The type of vocoder processing (i.e., tone and noise vocoders) produced little differences in sentence-recognition performance in both languages. Incidentally, the AE AzBio sentences and the MC HINT sentences had similar recognition performance under vocoder processing. Such similarity was further confirmed under noise conditions in experiment III, where the performance-intensity functions of the two sets of sentences were closely matched.

CONCLUSIONS

The HINT and AzBio sentence materials developed in AE and MC differ in level of difficulty. The AE AzBio and the MC HINT sentence materials are similar in level of difficulty. In cross-language comparative research, the MC HINT and the AE AzBio sentences should be chosen for the respective language as the target sentence-recognition test materials.

Comparison of the development of early auditory and preverbal skills in Mandarin-Speaking children with cochlear implants with and without additional disabilities

Background: Few studies had assessed the auditory and preverbal skills of very young cochlear implant (CI) children with additional disabilities (AD) over a long period, especially in China.Aims/Objectives: The aim of this study was to compare the early auditory and preverbal developmental trajectories in CI children with and without AD.Material and Methods: The LittlEARS^® Auditory Questionnaire (LEAQ) was employed. 29 typically developing (TD) children and 17 with AD were involved (age at implantation less than 2 years).Results: All children showed significant improvement in total LEAQ scores with CI use. Children with cerebral palsy (CP), developmental delay (DD) and white matter lesions (WML) scored lower than TD children since 3 months of CI use; a decreasing trend was observed from 24, 18 and 18 months of CI use, respectively. Children with higher nonverbal developmental quotients exhibited superior early auditory and preverbal skills.Conclusions and significance: The development of early auditory and preverbal skills among CI-using children progressed more slowly in those with AD (CP, DD or WML) than in TD children, but the differences between the two groups gradually diminished over time. Nonverbal cognitive status has a positive effect on early auditory and preverbal abilities.

Development and Clinical Introduction of the Nurotron Cochlear Implant Electrode Array

As the only medical device used in the treatment for deafness, the cochlear implant has benefited to more than half a million individuals worldwide. However, the device has limited penetration due to its high cost, especially in low- and middle-income countries. China alone has 27.8 million deaf people, but less than 100,000 of them have received a cochlear implant. The Nurotron Venus device was developed to address the need for an affordable yet safe and effective cochlear implant. The present study describes the design, development, and evaluation of the Nurotron intracochlear electrode array. The standard array is 22 mm in length from the round window marker to the apical tip of the carrier and has 24 electrodes, with a surface area of 0.32 mm2 and center-to-center spacing of 0.85 mm. The Nurotron array has been tested to meet the mechanical, chemical, and electrical requirements specified by the ISO Standard 14708-07. Human temporal bone and clinical trial results showed that the Nurotron array is easy to insert (7.8/10 rating with 10 indicating the highest ease of use) and has a low complication rate (12.5%) of severe insertion trauma while achieving high device stability and reliability (6 array failures in 43,000 patient years of experience). As a critical component, the Nurotron array has contributed to the high level of Nurotron implant speech performance, equivalent to that produced by other existing devices. The Nurotron device has benefited 10,000 deaf people and helped reduce the unit cost from US$25,000 in 2011 to US$4,620 in 2017 through the Chinese Government Tender Program. New, slim, and micromachined electrodes are being developed to further improve performance and accessibility.

The cochlear implant and possibilities for narrowing the remaining gaps between prosthetic and normal hearing

Background

The cochlear implant has become the standard of care for severe or worse losses in hearing and indeed has produced the first substantial restoration of a lost or absent human sense using a medical intervention. However, the devices are not perfect and many efforts to narrow the remaining gaps between prosthetic and normal hearing are underway.

Objective

To assess the present status of cochlear implants and to describe possibilities for improving them.

Results

The present-day devices work well in quiet conditions for the great majority of users. However, not all users have high levels of speech reception in quiet and nearly all users struggle with speech reception in typically noisy acoustic environments. In addition, perception of sounds more complex than speech, such as most music, is generally poor unless residual hearing at low frequencies can be stimulated acoustically in conjunction with the electrical stimuli provided by the implant. Possibilities for improving the present devices include increasing the spatial specificity of neural excitation by reducing masking effects or with new stimulus modes; prudent pruning of interfering or otherwise detrimental electrodes from the stimulation map; a further relaxation in the criteria for implant candidacy, based on recent evidence from persons with high levels of residual hearing and to allow many more people to benefit from cochlear implants; and “top down” or “brain centric” approaches to implant designs and applications.

Conclusions

Progress in the development of the cochlear implant and related treatments has been remarkable but room remains for improvements. The future looks bright as there are multiple promising possibilities for improvements and many talented teams are pursuing them.