Perceptual and acoustic invariance for place of articulation in diffuse stop consonants

Abstract

A recent investigation of acoustic invariance for place of articulation in diffuse stop consonants [Lahiri and Blumstein, J. Acoust. Soc. Am. Suppl. 1 70, S39 (1981)] has shown that current theories of acoustic invariance cannot distinguish labial from dental stops. Analysis of natural speech utterances suggested that there was acoustic invariance for labial and dental consonants, but based on the relative changes in the distribution of energy at high and low frequencies from the burst release to the onset of voicing. In this study, we attempted to determine whether the relative changes in the spectral characteristics elaborated by Lahiri and Blumstein would play a role in the perception of place of articulation in diffuse stop consonants. Prototype CV syllables ([b d] in the context of [i e a o u]) were generated based on natural speech tokens. The gross shape of the spectrum was manipulated first at the burst onset, then at the onset of voicing, such that the stimulus configuration had the spectral properties for labial or dental consonants while the formant frequencies and transition values were appropriate to the contrasting place of articulation. Results showed perceptual shifts for both labial and dental consonants in the context of [i] and [el, but not for the back vowels. Changing the prototype stimuli for the latter by using a mid‐value F2 in the test stimuli did have some perceptual effects on place of articulation. [Supported in part by an NIH grant.]