Related Experiment Video
Updated: May 29, 2026
An Automated System for Sound Localization Testing in Hearing-Impaired Listeners
Published on: March 13, 2026
The speech intelligibility benefit of a unilateral wireless system for hearing-impaired adults
William M Whitmer1, Christopher G Brennan-Jones, Michael A Akeroyd
1MRC Institute of Hearing Research (Scottish Section), Glasgow, UK. bill@ihr.gla.ac.uk
Objective:
This study measured the effects of two previously untested practical considerations-venting and transmission delays-on speech intelligibility in a simulated unilateral wireless system, where a target signal in background noise was transmitted wirelessly to the hearing-impaired (HI) listener.
Design:
Speech reception thresholds (SRTs) relative to the signal-to-noise ratio (SNR) were measured by varying the surrounding babble noise level. The target signal was presented at 0° azimuth in the soundfield and unilaterally via an insert earphone, using open and closed fittings with simulated-wireless delays ranging between 0-160 ms. SRTs were also measured unaided and with participants' current hearing aid(s).
Study Sample:
Thirty-three mild-to-moderate sensorineural HI adults participated in the experiment.
Results:
For an open fitting, the results showed a 5-dB SNR benefit in SRT compared to unaided performance at shorter delays. For a closed fitting, the majority of participants could accurately recognize speech below - 20 dBSNR across delays.
Conclusions:
These results highlight the efficacy of wireless systems with HI adults. Speech-intelligibility benefits are affected by transmission delays only when the delay is greater than 40 ms and the coupling is vented.
