Dr. Begault et T. Erbe, MULTICHANNEL SPATIAL AUDITORY DISPLAY FOR SPEECH COMMUNICATIONS, Journal of the Audio Engineering Society, 42(10), 1994, pp. 819-825
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.