Influence of signal enhancement algorithms on auditory movement detection in acoustically complex situations

So far, little is known about how hearing loss and hearing aid (HA) signal processing impact spatial hearing and/or movement perception in complex environments. Previously, we showed that concurrent distractor sounds impair the detectability of left-right source movements and reverberation that of near-far source movements for older hearing-impaired (OHI) listeners (Lundbeck et al, Trends Hear 2017). In a headphone-based follow-up study, we investigated ways of improving these deficits with computer-simulated HA processing (Lundbeck et al, Trends Hear 2018). To that end, we examined the impact of two beamforming algorithms and a binaural coherence-based noise reduction scheme on the acoustic cues underlying movement perception. We found that the applied processing led to greater monaural spectral changes as well as increases in signal-to-noise ratio and direct-to-reverberant energy ratio in our test stimuli. Furthermore, we found that it partly restored source movement detection for OHI listeners in the presence of distractor sounds. In a third study, we extended these findings towards equivalent measurements made with a loudspeaker array and wearable HAs (Lundbeck et al, under review). For a group of 13 OHI listeners, we found no differences in left-right or near-far target movement detectability. In this contribution, we discuss the results from this project with a focus on the potential and difficulties associated with measuring spatial awareness perception in complex acoustic environments.