Range effects for speech and nonspeech Judgments of sine wave stimuli

Abstract

In a previous paper [Williams et al., J. Acoust. Soc. Am. Suppl. 1 74, S66 (1983)], we demonstrated that an influence of consonantal context on vowel perception [B. Lindblom and M. Studdert‐Kennedy, J. Acoust. Soc. Am. 42, 830–843 (1967)] is obtained for sine wave as well as for formant stimuli. We showed further that a similar influence is not apparent when the sine wave stimuli were judged in terms of pitch rather than speech categories. Category boundaries for pitch judgments fell at the midpoint of the continua while those for isolated vowels and vowels in consonantal context were arrayed to the left and right of the midpoint, respectively. In the present set of experiments, we sought to assess the stability of the speech and nonspeech category boundaries by testing an effect of stimulus range on listeners' categorizations. To do this, we removed the lower one‐third from each of the continua used in our previous experiment. Pilot results replicate our earlier findings: once again, pitch boundaries divided the continua in half and speech boundaries fell to either side of the midpoint. Nonetheless, these data show that speech as well as pitch judgments are subject to range effects. [Work supported by NICHD.]