Improving auditory externalization for hearing-aid remote microphones
James Mitchell Kates, Kathryn Hoberg Arehart · 2017
Combining a remote wireless microphone (RM) with hearing aids often improves speech intelligibility for hearing-impaired listeners. However, the head-related acoustic cues that contribute to sound externalization are bypassed when a direct signal link is used. The result is an apparent sound source located within the head of the listener rather than at the talker position. This paper describes using a structural binaural model combined with simulated room reverberation to produce an externalized RM sound source. The binaural model simulates sound propagation around the head, the reflections generated by the pinna, the directional filtering provided by the pinna protrusion from the head, and the ear-canal resonance. The simulated room reverberation uses a two-dimensional virtual image model. The signal-processing blocks used in the binaural model are presented along with examples of the entire system response.