Perception of some consonant contrasts in noise

Abstract

The goal of the present study is to examine the acoustic properties that listeners use to distinguish between speech sounds when these sounds are presented in noise. A series of perceptual experiments was conducted using natural stimuli consisting of nonsense CV syllables, where C was either /m/,/n/,/b/, or/d/, and V was either /ɑ/, /iy/, or /ow/. The stimuli were degraded by adding various levels of white noise and were presented to subjects in identification tests. Preliminary results show that when the noise is at a level such that the transition of the second formant frequency of the vowel is masked, confusions between the place of articulation for the stimuli occur. Noise levels for which confusions in manner of articulation occur can also be predicted from masking theory. These results are compared with results reported earlier [e.g., Miller and Nicely (1954)] where the thresholds of idenfication were described in terms of the signal‐to‐noise ratio. These results will be discussed further in terms of the acoustic theory of speech production and the masking theory of the auditory system. [Work supported in part by an NIH grant.]