Abstract:
Recent findings [R. N. Ohde and A. H. Perry, J. Acoust. Soc. Am. 96, 1303--1313 (1994); R. N. Ohde and M. T. Ochs, J. Acoust. Soc. Am. (in press)] indicate that a peripheral mechanism may be involved in processing spectral discontinuities from the nasal murmur to vowel onset. The purpose of the current study was to assess the level of perceptual integration of nasal consonants. The speech sample was comprised of CV syllables produced by an adult female and male, and consisted of either [m] or [n] in the context of four vowels [i (ae ligature) u (open aye)]. Twelve adults identified the place of articulation of the nasal before and after the insertion of periods of silence ranging from 0 to 1000 ms between murmur and vowel transition segments of varying duration. In the experimental conditions, the murmur and the vowel were split and presented to different ears. The major findings were as follows: (1) Perceptual integration was significantly greater for the murmur + transition presented monaurally with a 0-ms gap duration than the comparable split channel condition; and (2) across the split channel conditions, identification of place of articulation of the nasal was near chance level (50%). The results support the conclusion that a major component of the observed perceptual integration effect is based on a peripheral mechanism. [Work supported by NIH and a Vanderbilt University Research Council Grant.]