Maintaining intelligibility at high intensities with arrays of subcritical width speech bands and interpolated noise

Abstract

Speech intelligibility normally declines at high intensities, but this "rollover" effect decreases when steep filtering reduces sentences to an array of rectangular subcritical bands. The present study found that interpolating low intensity noise between the speech bands further decreases rollover, supporting the hypothesis that rollover is normally reduced by lateral inhibition of input from rate-saturated auditory nerve fibers. With noise also present within the speech (a 15 dB signal-to-noise ratio) an array of 6%-wide speech bands with interpolated noise was found to be 9% more intelligible at 100 dB than a spectrally continuous band of speech covering the same frequency range.