MULTICHANNEL SPATIAL AUDITORY DISPLAY FOR SPEECH COMMUNICATIONS

A spatial auditory display for multiple speech communications was deve loped at NASA/Ames Research Center. Input is spatialized by the use of simplified head-related transfer functions, adapted for FIR filtering on Motorola 56001 digital signal processors. Hardware and firmware de sign implementations are overviewed for the initial prototype develope d for NASA-Kennedy Space Center. An adaptive staircase method was used to determine intelligibility levels of four-letter call signs used by launch personnel at NASA against diotic speech babble. Spatial positi ons at 30-degrees azimuth increments were evaluated. The results from eight subjects showed a maximum intelligibility improvement of about 6 -7 dB when the signal was spatialized to 60 or 90-degrees azimuth posi tions.