Fitting recommendations and clinical benefit associated with use of the NAL-NL2 hearing-aid prescription in Nucleus cochlear implant recipients

Abstract

Objective: For a group of cochlear implant recipients, who use hearing aids in the contralateral ear, the benefit of NAL-NL2 relative to a recipients’ own prescription was assessed. Whether there was a preferred frequency response and/or gain deviation from NAL-NL2 was then investigated. Design: Speech recognition and self-reported ratings of benefit were examined for the recipients’ own prescription compared to the NAL-NL2 prescription, in the bimodal and hearing-aid alone conditions. Paired-comparison of hearing-aid frequency response was conducted with default NAL-NL2 and two variants, a low frequency boost or cut. Using a loudness balancing procedure, the hearing-aid gain required to achieve equal loudness between the devices was measured. Study sample: Sixteen adults with post-lingual hearing loss. Results: A 22% increase in group median word score in quiet with use of NAL-NL2 in the hearing-aid alone condition. In the bimodal condition there was no improvement with NAL-NL2. Default NAL-NL2 frequency response was preferred by 67% of participants. For 56% of participants, the preferred gain to achieve loudness balance across bimodal devices was within 5-dB of prescribed values. Conclusions: The NAL-NL2 prescription provides a high level of clinical performance, and an acceptable frequency response and gain for most participants.

Key Words:

• Cochlear implant
• bimodal
• acoustic hearing
• hearing-aid prescription

Acknowledgements

The authors would like to thank the cochlear implant recipients and the Royal Victorian Eye and Ear Hospital. We thank Bev Sheridan for administrative support and Dr Peter Busby for his feedback on the paper. This research was funded by The HEARing Cooperative Research Centre, established through the Cooperative Research Centre Program, an Australian Government Initiative.

Declaration of interest

The authors declare no conflicts of interest.