Nasalance and nasality in children with cochlear implants and children with hearing aids

American Cochlear Implant Alliance Task Force Guidelines for Determining Cochlear Implant Candidacy in Children

This article summarizes the available evidence on pediatric cochlear implantation to provide current guidelines for clinical protocols and candidacy recommendations in the United States. Candidacy determination involves specification of audiologic and medical criteria per guidelines of the Food and Drug Administration. However, recommendations for a cochlear implant evaluation also should maintain flexibility and consider a child’s skill progression (i.e., month-for-month progress in speech, language, and auditory development) and quality of life with appropriately fit hearing aids. Moreover, evidence supports medical and clinical decisions based on other factors, including (a) ear-specific performance, which affords inclusion of children with asymmetric hearing loss and single-sided deafness as implant candidates; (b) ear-specific residual hearing, which influences surgical technique and device selection to optimize hearing; and (c) early intervention to minimize negative long-term effects on communication and quality of life related to delayed identification of implant candidacy, later age at implantation, and/or limited commitment to an audiologic rehabilitation program. These evidence-based guidelines for current clinical protocols in determining pediatric cochlear implant candidacy encourage a team-based approach focused on the whole child and the family system.

Rating the overall speech quality of hearing-impaired children by means of comparative judgements

OBJECTIVE

Acoustic measurements have shown that the speech of hearing-impaired (HI) children deviates from the speech of normally hearing (NH) peers. The aim of the present study is to examine whether listeners with varying degrees of experience with (HI) children's speech perceive a difference in the overall speech quality of seven-year-old NH children and their HI peers who received a device before the age of two.

METHOD

Short speech samples of seven children with NH, seven children with an acoustic hearing aid (HA) and seven children with a cochlear implant (CI) were judged by three groups of listeners (audiologists, primary school teachers and inexperienced listeners) in a comparative judgement task. In this task, listeners compared stimuli in pairs and decided which stimulus sounded better, leading to a ranking of the stimuli according to their overall speech quality.

RESULTS

The ranking showed that the overall speech quality differed considerably for HI and NH children. The latter group had a significantly higher overall speech quality than HI children. In the group of HI children, children with CI were ranked higher than children with HA. Moreover, length of device use was found to have a significant effect in the group of children with CI: longer device experience led to better ratings. This effect was significantly less strong in HA children. No significant differences were found between the three groups of listeners.

CONCLUSION

Listeners agree that the speech of NH children sounds better than the speech of HI children. This result indicates that even after almost seven years of device use, the speech of HI children still differs from the speech of NH children. The overall speech quality of CI children was better than that of HA children, and this effect increased with longer device use. No effect of listeners' experience with (NH and/or HI) children's speech was established.

Effects of Error Experience on Learning to Lower Speech Nasalance Level

Purpose This research aims to examine the effects of error experience when learning to speak with lowered nasalance level. Method A total of 45 typical speakers were instructed to learn to lower speech nasalance level in either an errorless (restricted possibility for committing errors) or an errorful (unrestricted possibility for committing errors) learning condition. The nasality level of the participants' speech was measured by a nasometer and quantified by nasalance scores (in percent). Errorless learners practiced producing speech with lowered nasalance level with a threshold nasalance score of 50% (the easiest target) at the beginning, which gradually decreased to a threshold of 10% (the most difficult target) at the end. The same set of threshold targets was presented to errorful learners, but in reverse order. Errors were defined by the proportion of speech, with a nasalance score exceeding the threshold. Retention and transfer tests were administered. Results Errorless learners displayed fewer errors and lower mean nasalance scores than errorful learners during the acquisition phase. Furthermore, errorless learners achieved lower mean nasalance scores than errorful learners in the retention and transfer tests. Conclusion These results suggest that errorless learning is more effective than errorful learning and that error experience has a detrimental effect on the acquisition of a novel speech motor task that requires minimization of the nasality level. Errorless learning may be a useful paradigm for the intervention and management of hypernasality in clinical settings where behavioral treatments are needed.

Basic Measures of Prosody in Spontaneous Speech of Children With Early and Late Cochlear Implantation

PURPOSE

Relative to normally hearing (NH) peers, the speech of children with cochlear implants (CIs) has been found to have deviations such as a high fundamental frequency, elevated jitter and shimmer, and inadequate intonation. However, two important dimensions of prosody (temporal and spectral) have not been systematically investigated. Given that, in general, the resolution in CI hearing is best for the temporal dimension and worst for the spectral dimension, we expected this hierarchy to be reflected in the amount of CI speech's deviation from NH speech. Deviations, however, were expected to diminish with increasing device experience.

METHOD

Of 9 Dutch early- and late-implanted (division at 2 years of age) children and 12 hearing age-matched NH controls, spontaneous speech was recorded at 18, 24, and 30 months after implantation (CI) or birth (NH). Six spectral and temporal outcome measures were compared between groups, sessions, and genders.

RESULTS

On most measures, interactions of Group and/or Gender with Session were significant. For CI recipients as compared with controls, performance on temporal measures was not in general more deviant than spectral measures, although differences were found for individual measures. The late-implanted group had a tendency to be closer to the NH group than the early-implanted group. Groups converged over time.

CONCLUSIONS

Results did not support the phonetic dimension hierarchy hypothesis, suggesting that the appropriateness of the production of basic prosodic measures does not depend on auditory resolution. Rather, it seems to depend on the amount of control necessary for speech production.

Can listeners hear the difference between children with normal hearing and children with a hearing impairment?

Acoustic measurements have shown that the speech of hearing-impaired (HI) children differs from that of normally hearing (NH) children, even after several years of device use. This study focuses on the perception of HI speech in comparison to NH children's speech. The purpose of this study was to investigate whether adult listeners can identify the speech of NH and HI children. Moreover, it is studied whether listeners' experience and the children's length of device use play a role in that assessment. For this study, short utterances of 7 children with a cochlear implant (CI), 7 children with an acoustic hearing aid (HA) and 7 children with NH were presented to 90 listeners who were required to specify the hearing status of each speech sample. The judges had different degrees of familiarity with hearing disorders: there were 30 audiologists, 30 primary schoolteachers and 30 inexperienced listeners. The results show that the speech of children with NH and HI can reliably be identified. However, listeners do not manage to distinguish between children with CI and HA. Children with CI are increasingly identified as NH with increasing length of device use. For children with HA, there is no similar change with longer device use. Also, experienced listeners seem to display a more lenient attitude towards atypical speech, whereas inexperienced listeners are stricter and generally consider more utterances to be produced by children with HI.