Investigation of the current supply system for hearing aids at stores in Japan

OBJECTIVE

This study aimed to examine the status of the supply system for hearing aids at stores in Japan.

METHODS

This was a cross-sectional, observational study. We mailed questionnaires to 4502 hearing aid stores in Japan and analyzed the responses.

RESULTS

Of the 4502 stores, 1032 (23%) responded. Most stores accessed audiogram information and adjusted hearing aids using computer fitting software. Overall, 43% of the stores only used the manufacturer's original prescription formula to adjust the hearing aid, and 47% of stores lacked a device for measuring the frequency response of the hearing aids. Moreover, 20% of the stores lacked both a sound field threshold measurement system and a real-ear measurement device. Objective evaluations, including functional gain, rear-ear insertion gain, and frequency response data, were not performed by 14% stores. Speech-language-hearing therapists were present in only 5.6% stores.

CONCLUSION

The findings revealed several key shortcomings in the hearing aid supply system at hearing aid stores in Japan.

Can real-ear insertion gain deviations from generic fitting prescriptions predict self-reported outcomes?

OBJECTIVE

The aim of this study was to determine whether the differences in insertion gains from the first fit to generic prescriptions of hearing aids can predict the self-reported hearing aid (HA) outcomes for first-time and experienced HA users.

DESIGN

This was a prospective observational study.

STUDY SAMPLE

The study included 885 first-time and 330 experienced HA users with a valid real-ear measurement on both ears and answers to the abbreviated version of the Speech, Spatial, and Quality of Hearing (SSQ12) and the International Outcome Inventory for Hearing Aids (IOI-HA) questionnaires.

RESULTS

K-means clustering of gain differences between individual real-ear insertion gain to three generic gain prescriptions (NAL-NL2, NAL-RP, and one-third gain rules) was performed. The gain difference at higher frequencies generally differentiated the clusters. The experienced users in the cluster with fittings closest to NAL-NL2 and NAL-RP prescription were found to exhibit a higher IOI-HA Factor 1 score (representing the overall benefit of the hearing aid use). The gain differences to generic prescription did not affect other self-reported outcomes for first-time and experienced HA users.

CONCLUSION

The experienced HA users with minimal gain deviations from generic prescriptions reported better self-perceived benefits than users with larger deviations. However, this was not apparent in first-time users.