Benefits of Beamforming With Local Spatial-Cue Preservation for Speech Localization and Segregation

A study was conducted to examine the benefits afforded by a signal-processing strategy that imposes the binaural cues present in a natural signal, calculated locally in time and frequency, on the output of a beamforming microphone array. Such a strategy has the potential to combine the signal-to-noise ratio advantage of beamforming with the perceptual benefit of spatialization to enhance performance in multitalker mixtures. Participants with normal hearing and with hearing loss were tested on both speech localization and speech-on-speech masking tasks. Performance for the spatialized beamformer was compared with that for three other conditions: a reference condition with no processing, a beamformer with no spatialization, and a hybrid beamformer that operates only in the high frequencies to preserve natural binaural cues in the low frequencies. Beamforming with full-bandwidth spatialization supported speech localization and produced better speech reception thresholds than the other conditions.