Own-Voice Perception with Different Processing Delays in Open-Fit Hearing Aids

In open-fit hearing aids (HAs), the interaction between the direct and processed sound leads to comb-filtering and, thus, perceived coloration effects. The magnitude of these effects depends on the level difference between the direct and processed sound and on the processing delay. A critical issue for HA uptake and use is own-voice perception, which the current study focused on. Its aims were to investigate (1) whether short processing delay is preferred over longer delays, (2) how processing delay influences different perceptual dimensions related to own-voice perception, and (3) whether spectral discrimination abilities can predict delay preference. Twenty-four individuals with mild-to-moderate hearing impairment participated. Using prototype receiver-in-the-canal HAs, processing delays of 0.5, 5, and 10 ms were compared. Delay preference was assessed using a paired-comparison task. Perceptual dimensions relating to own-voice perception were investigated using a customized version of the "Own Voice Qualities" questionnaire. Spectral discrimination abilities were assessed using a spectral ripple discrimination (SRD) task. The analyses showed that the 0.5-ms delay was preferred over the longer delays. Furthermore, the 0.5-ms delay received better ratings related to tonality perception (e.g., attributes such as metallic and sharp) and own-voice quality compared to the 10-ms delay. SRD abilities did not predict delay preference. Overall, these results provide insights into how open-fit HAs can be optimized with respect to own-voice perception.