Influence of signal enhancement algorithms on auditory movement detection in acoustically complex situations
Micha Lundbeck, Giso Grimm, Volker Hohmann, Lars Bramsløw, Tobias Neher · University of Southern Denmark Research Portal (University of Southern Denmark) · 2018
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.