Effects of Hearing Loss and Hearing Aid Directionality on Search Behavior in Complex Audio-Visual Environments

Listeners with hearing loss often struggle to understand speech in the presence of multiple competing speakers. These difficulties become more pronounced with an increase in the number of speakers and the presence of reverberation. Here, we investigated how both normal-hearing and hearing-impaired listeners localize and identify a specific speaker in reverberant audio-visual scenes. The audio-visual scenes were presented using a 64-channel loudspeaker array and virtual-reality glasses. These scenes varied in terms of the target speaker’s position, the number of competing speakers, and the spatial separation between them. The participants were tested in different conditions: without assistance, with omnidirectional hearing-aid settings, and with directional settings. Amplification was based on NAL-NL2 target gains to ensure audibility compensation. The outcome measures included accuracy in speaker localization, response time, and the trajectories of head movements and eye-gazes during task completion. Currently, data collection and analysis are ongoing. We anticipate that this study will shed light on strategies used by listeners to identify target speech in complex listening environments and on how hearing loss and directional processing impact their behavior.