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

Abstract

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.

Keywords:

• Real-ear measurement
• gain prescription
• hearing aids
• self-reported outcome

Acknowledgments

The authors acknowledge the effort of Michael Lyhne Gaihede, Dan Dupont Hougaard, Erik Schmidt, Vijay Narne, and Gérard Loquet during the data collection and extraction of Real-Ear Measurements. The authors also thank Brent Edwards, Scott Brewer, and NAL for providing the NAL-NL2 developer kit and Nikolai Bisgaard for facilitation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Innovation Fund Denmark [Grand Solutions 5164-00011B] (Better hEAring Rehabilitation project), Oticon, GN Hearing, Widex-Sivantos Audiology, and other partners (Aalborg University, University of Southern Denmark, the Technical University of Denmark, Force, Aalborg, Odense and Copenhagen University Hospitals).