No abstract

No abstract

In VCV nonsense forms (such as /epsilondepsilon/, while both the CV transition and the VC transition are perceptible in isolation, the CV transition dominates identification of the stop consonant. Thus, the question arises, what role, if any, do VC transitions play in word perception? Stimuli were two-syllable English words in which the medial consonant was either a stop or a fricative (e.g., "feeding" and "gravy"). Each word was constructed in three ways: (1) the VC transition was incompatible with the CV in either place, manner of articulation, or both; (2) the VC transition was eliminated and the steady-state portion of first vowel was substituted in its place; and (3) the original word. All versions of a particular word were identical with respect to duration, pitch contour, and amplitude envelope. While an intelligibility test revealed no differences among the three conditions, data from a paired comparison preference task and an unspeeded lexical decision task indicated that incompatible VC transitions hindered word perception, but lack of VC transitions did not. However, there were clear differences among the three conditions in the speeded lexical decision task for word stimuli, but not for nonword stimuli that were constructed in an analogous fashion. We discuss the use of lexical tasks for speech quality assessment and possible processes by which listeners recognize spoken words.

A series of adaptation experiments was conducted to investigate the role of initial noise bursts and transitions as cues to place of articulation in stop consonants. A test continuum was constructed consisting of 14 synthetic stimuli in which 'the transitions of formant two and formant three were systematically varied to range along the [b dg] phonetic dimension. The adapting stimuli consisted of full-cue stimuli in which place of hrticulation was signaled by burst as well as transitions; partial-cue stimuli in which place was signaled by transitions only; and conflicting-cue stimuli in which the burst frequency signaled one phonetic dimension (e.g., [d]), whereas the transitions signaled another (e.g., [g]). Adaptation with either the partial-or full-cue stimuli produced significant shifts in phonetic boundaries for the test continuum, with the full-cue stimuli producing a slightly greater boundary shift. The conflicting-cue stimuli produced no significant shifts in adaptation. Moreover, adaptation effects seemed to be a function of the acoustic attributes of the stimulus independent of the phonetic label given the stimulus by the subject. These results were interpreted in terms of a model that postulates a set of integrated properties characterized by the short-term acoustic spectrum sampled. at the abrupt amplitude discontinuity at consonantal release, and a set of simple properties consisting of individual attributes of the test stimuli such as burst frequency.