Acoustic analysis and perceptual effect of variation in the amplitude envelopes of /b/ and /w/

Abstract

Relative energy change at consonantal release has been proposed as an acoustic property, invariant across vowel contexts and speakers, to distinguish between stops and glides [M. Mack and S. E. Blumstein, J. Acoust. Soc. Am. 73, 1739–1750 (1983)]. We followed the procedures of Mack and Blumstein to measure distributions of energy in /bV/ and /wV/ syllables, spoken by two speakers before five vowels. Results for one speaker matched those of Mack and Blumstein; results for a second speaker did not. In a subsequent perceptual experiment, amplitude envelopes of /bV/ and /wV/ syllables containing the same vowels were crossed. Envelope crossing had little effect on the syllables of one speaker: Nearly all were perceived as originally produced. For the second speaker /w/ to crossing also had little effect, but /b/ to /w/ crossing elicited more than 75% /b/ responses, particularly before /a/. Thus although relative energy change at consonantal release may separate /b/ from /w/, acoustically and perceptually, in some contexts, for some speakers, it is evidently not invariant. [Work supported by NICHD.]