Speech perception in congenitally, pre-lingually and post-lingually deaf children expressed in an equivalent hearing loss value

Prenatal Alcohol Exposure and Suspected Hearing Impairment Among Children: A Population-based Retrospective Cohort Study

Aims

This study aimed to examine the association between prenatal alcohol exposure and hearing impairment among Japanese children using early childhood health check-up data.

Methods

This retrospective cohort study used population-based health check-up data for children who were born between April 2000 and March 2013 in Hofu city, Japan. Logistic regression models were used to evaluate the association between prenatal alcohol exposure and hearing impairment among children at the age of 36 months. The models were adjusted for mother's age, smoking habit, child sex, birth weight, birth order, history of otitis media and familial history of hearing impairment.

Results

Among the 16,211 registered children, 10,680 children had maternal gestational information and underwent a health check-up at the age of 36 months. A total of 10,562 children were included in the analyses, which revealed that 640 children required a re-examination for hearing impairment, 157 children required a detailed examination for hearing impairment and 83 children were receiving treatment for hearing impairment at 36 months. Prenatal alcohol exposure was independently associated with suspected hearing impairment among children after adjusting for potential confounders.

Conclusions

Our findings suggest that prenatal alcohol exposure may adversely affect the auditory system of children.

Short Summary

Prenatal alcohol exposure was associated with suspected hearing impairment among children at 36 months, based on the findings of a population-based retrospective cohort study that used health check-up data from 10,562 Japanese children.

Development of perception and perceptual learning for multi-timescale filtered speech

The perception of temporally changing auditory signals has a gradual developmental trajectory. Speech is a time-varying signal, and slow changes in speech (filtered at 0-4 Hz) are preferentially processed by the right hemisphere, while the left extracts faster changes (filtered at 22-40 Hz). This work examined the ability of 8- to 19-year-olds to both perceive and learn to perceive filtered speech presented diotically for each filter type (low vs high) and dichotically for preferred or non-preferred laterality. Across conditions, performance improved with increasing age, indicating that the ability to perceive filtered speech continues to develop into adolescence. Across age, performance was best when both bands were presented dichotically, but with no benefit for presentation to the preferred hemisphere. Listeners thus integrated slow and fast transitions between the two ears, benefitting from more signal information, but not in a hemisphere-specific manner. After accounting for potential ceiling effects, learning was greatest when both bands were presented dichotically. These results do not support the idea that cochlear implants could be improved by providing differentially filtered information to each ear. Listeners who started with poorer performance learned more, a factor which could contribute to the positive cochlear implant outcomes typically seen in younger children.

Comprehension of Degraded Speech Matures During Adolescence

PURPOSE

The aim of the study was to compare comprehension of spectrally degraded (noise-vocoded [NV]) speech and perceptual learning of NV speech between adolescents and young adults and examine the role of phonological processing and executive functions in this perception.

METHOD

Sixteen younger adolescents (11-13 years), 16 older adolescents (14-16 years), and 16 young adults (18-22 years) listened to 40 NV sentences and repeated back what they heard. They also completed tests assessing phonological processing and a variety of executive functions.

RESULTS

Word-report scores were generally poorer for younger adolescents than for the older age groups. Phonological processing also predicted initial word-report scores. Learning (i.e., improvement across training times) did not differ with age. Starting performance and processing speed predicted learning, with greater learning for those who started with the lowest scores and those with faster processing speed.

CONCLUSIONS

Degraded (NV) speech comprehension is not mature even by early adolescence; however, like adults, adolescents are able to improve their comprehension of degraded speech with training. Thus, although adolescents may have initial difficulty in understanding degraded speech or speech as presented through hearing aids or cochlear implants, they are able to improve their perception with experience. Processing speed and phonological processing may play a role in degraded speech comprehension in these age groups.

Cost Effectiveness of Childhood Cochlear Implantation and Deaf Education in Nicaragua: A Disability Adjusted Life Year Model

INTRODUCTION

Cochlear implantation (CI) is a common intervention for severe-to-profound hearing loss in high-income countries, but is not commonly available to children in low resource environments. Owing in part to the device costs, CI has been assumed to be less economical than deaf education for low resource countries. The purpose of this study is to compare the cost effectiveness of the two interventions for children with severe-to-profound sensorineural hearing loss (SNHL) in a model using disability adjusted life years (DALYs).

METHODS

Cost estimates were derived from published data, expert opinion, and known costs of services in Nicaragua. Individual costs and lifetime DALY estimates with a 3% discounting rate were applied to both two interventions. Sensitivity analysis was implemented to evaluate the effect on the discounted cost of five key components: implant cost, audiology salary, speech therapy salary, number of children implanted per year, and device failure probability.

RESULTS

The costs per DALY averted are $5,898 and $5,529 for CI and deaf education, respectively. Using standards set by the WHO, both interventions are cost effective. Sensitivity analysis shows that when all costs set to maximum estimates, CI is still cost effective.

CONCLUSION

Using a conservative DALY analysis, both CI and deaf education are cost-effective treatment alternatives for severe-to-profound SNHL. CI intervention costs are not only influenced by the initial surgery and device costs but also by rehabilitation costs and the lifetime maintenance, device replacement, and battery costs. The major CI cost differences in this low resource setting were increased initial training and infrastructure costs, but lower medical personnel and surgery costs.

Is there a deafness duration limit for cochlear implants in post-lingual deaf adults?

CONCLUSION

Patients with post-lingual deafness should not be excluded from cochlear implantation (CI) on the basis of duration of deafness. We found that the prognosis was favorable in patients who developed deafness after adolescence, even in those with extremely long-term deafness.

OBJECTIVES

CI is an effective treatment for post-lingual deafness. However, it remains unclear whether CI would benefit patients with extremely long-term deafness. We evaluated the auditory performance after CI of patients who had been deaf for more than 30 years.

METHODS

The study enrolled 81 adults with post-lingual deafness. Speech perception tests were performed preoperatively and 12 months postoperatively, and factors affecting the postoperative auditory performance were investigated. The subjects were divided into groups according to the duration of deafness and the postoperative speech perception scores were compared.

RESULTS

A marked improvement in the open-set speech perception scores (mono/disyllabic words and sentences) after implantation was seen in all groups, and no significant difference in the improvement in speech perception scores was observed among the groups. Age at onset of deafness was closely related to the postoperative performance, and patients who had lost their hearing before adolescence performed poorly.

Cochlear blood flow and speech perception ability in cochlear implant users

OBJECTIVE

The effect of cochlear blood flow (CBF) on speech perception ability in cochlear implant (CI) users has not been reported. We investigated various factors influencing speech perception including CBF in CI users.

PATIENTS

Eighty-two patients who received CI surgery at an academic hospital.

METHODS

CBF was measured during CI surgery using laser Doppler flowmetry. The speech perception level was measured after a sufficient interval after CI surgery. Multivariate analysis was used to evaluate the influences of age, duration of deafness, sex, cause of deafness, and CBF on the speech perception level.

RESULTS

CBF decreased significantly with age but was not related to the speech perception level. In patients with congenital hearing loss, the speech perception level was significantly worse in children who received a CI at 3 years of age than in those who received a CI at 2 years of age or younger. Duration of deafness before CI surgery had deteriorative effects on the speech perception level.

CONCLUSION

CBF may be associated with progression of hearing loss. However, measuring CBF during CI surgery is not useful for predicting postoperative speech perception.

Cochlear implantation in children with postlingual hearing loss

OBJECTIVES/HYPOTHESIS

Although it is clear that early auditory stimulation through cochlear implantation (CI) has been shown to improve speech and language development trajectories for children with prelingual hearing loss, data supporting implantation in postlingual children are mostly lacking. The purpose of this study was to characterize speech perception abilities following CI in a group of children with previously well-developed language abilities.

STUDY DESIGN

Retrospective analysis.

METHODS

Twenty-eight hearing-impaired children who received CIs were selected for study based on the presence of well-developed spoken language skills before implantation. Fifteen children with prelingual hearing loss served as a control group. Speech perception skills were assessed using developmentally appropriate measures.

RESULTS

Children with postlingual hearing loss showed a statistically significant improvement in open-set speech perception scores as early as 6 months following CI, whereas prelingual children demonstrated significant improvements only after 24 months of use. Despite these early disparities in performance, the two groups were similar 36 months after implantation and beyond (60 months of implant use).

CONCLUSIONS

Children with well-developed language abilities before CI showed substantial (and statistically significant) early improvements in open-set speech perception abilities following implantation that continued beyond 2 years of follow-up. These results suggest that postlingual children are excellent candidates for CI.

A comparison of the speech recognition and pitch ranking abilities of children using a unilateral cochlear implant, bimodal stimulation or bilateral hearing aids

OBJECTIVE

The present study compared the speech recognition and pitch ranking abilities of normally hearing children (n=15) to children using a cochlear implant (CI) alone (n=8), bilateral hearing aids (HAs) (n=6), or bimodal stimulation (BMS) (n=9). It was hypothesised that users of BMS would score higher on tasks of speech and pitch perception than children using a CI alone, but not children using HAs.

METHODS

Participants were assessed on tasks of monosyllabic word recognition in quiet, sentence recognition in quiet and noise (10 dB signal-to-noise ratio), and a pitch ranking task using pairs of sung vowels one, half, and a quarter of an octave apart.

RESULTS

There were no significant differences between the mean percentage-correct scores of the four participant groups for either words in quiet or sentences in quiet and noise. However, the proportion of bimodal users who scored >80% correct (80%) was significantly greater than the proportion of high-scoring unilateral CI (25%) or bilateral HA users (17%). Contrary to expectations, there was also no significant difference between the pitch ranking scores of users of BMS and users of a CI alone for all three interval sizes (p<0.05, RM-ANOVA). However participants using only acoustic hearing (i.e. the NH and HA groups) scored significantly higher than participants using electrical stimulation (i.e. the CI and BMS groups) on the pitch ranking task (p<0.05; RM-ANOVA).

CONCLUSIONS

Contrary to findings in postlingually deafened adults, we found no significant bimodal advantage for pitch perception in prelingually deafened children. However, the performance of children using electrical stimulation was significantly poorer than children using only acoustic stimulation. Further research is required to investigate the contribution of the non-implanted ears of users of BMS to pitch perception, and the effect of hearing loss on the development of pitch perception in children.