Article
The disadvantage of transparent hearing devices on speech intelligibility in normal-hearing listeners (de)
* Presenting author
Abstract:
Transparent hearing devices reproduce the acoustic environment heard by the user as naturally as possible, which is an important feature for hearables, but can also be understood as a basic operational mode of hearing aids. Previous studies showed detrimental effects of listening through transparent hearing devices on e.g., sound quality, localization, and speech perception, which depend on the quality of transparency. A rather surprising effect was a hearing device disadvantage on speech intelligibility when speech and noise come from the same direction and undergo identical processing by the device, such that the SNR at ear is not altered. In this contribution, we present a series of studies examining this effect and its origin by determining the speech intelligibility in a collocated setup with various devices, settings, and conditions. A hearing device disadvantage of 0.5 – 1 dB regarding the SNR at 50% speech intelligibility with the OLSA test was observed across all studies and devices, except for one commercial hearable. This disadvantage could be reduced but not removed by individualized equalization of the transfer function to that of the wearer’s open ear. Measurements at different levels speak against the hypothesis that the disadvantage is caused by self-noise or driver nonlinearities.