Perception of sine wave analogs of stop consonant place information

Abstract

Identification and discrimination procedures were used with nonspeech stimuli to investigate a possible auditory basis for categorical perception of place of articulation. One sinewave series consisted of linear frequency transitions (varying in onset frequency) followed by a steady-state portion. A second series was produced by combining each of the stimuli from the first series with a second tone (a rising initial transition followed by a steady state). The stimuli were modeled after the second and third formants of a stop consonant series varying in place of articulation. Subjects reliably sorted the one-tone-component series into three categories corresponding roughly to rising, flat, and falling transitions. The local maxima of subjects' discrimination functions fell near the labeling category boundaries. With the inclusion of the second tone, subjects reliably sorted the continuum into two, rather than three, categories. Further, a single discrimination maximum, located in the vicinity of the category boundary, was found for the two-component stimuli. The results suggest that auditory categories may underlie the perception of an analogous stop place series and that information is not extracted independently for each transition. Rather, the pattern of formant transitions seems to be the critical information that underlies the stop-place categories. [Work supported by NINCDS.]