Impact of Reference Microphone Selection on Binaural Cue Preservation for Directional Sources in Multi-microphone Hearing Aids

In this paper, we study the impact of reference microphone selection on binaural cue preservation for directional sources in digital hearing aids using the Binaural Minimum Variance Distortionless Response Beamformer (BMVDR). The preservation of the Interaural Transfer Function (ITF) for interfering signals, which are directional in nature, is studied, and it is shown, both theoretically and with a realistic simulation, that the binaural cue preservation is significantly influenced by the choice of the reference microphones for each of the ears - a finding which is counterintuitive in nature.