Effects of masking noise on auditory-nerve coding of vowels

Abstract

We have previously reported on the representation of steady-state vowels in terms of both average rate and temporal aspects of the discharge patterns of populations of auditory-nerve fibers [Sachs and Young, J. Acoust. Soc. Am. 66, 470–479 (1979); Young and Sachs, J. Acoust. Soc. Am. 66, 1381–1403 (1979)]. The previous results were based on recordings made in the absence of background noise. In this paper we report the results of a study in which responses of large populations of auditory-nerve fibers to steady-state vowels were recorded in the presence of broad band background noise. Evidence will be presented that in the CF ranges between the formant frequencies, responses evoked by the background noise can be suppressed by presentation of the vowel. At noise levels high enough to drive units into rate-saturation, phase-locked responses to the vowel can still be observed. [Supported by Grant No. NS12112 from NINCDS.]