Rhythmic effects in perception of continuous speech

Abstract

In experiments measuring reaction time (RT) to phoneme targets in sentences, earlier work produced slower RT when the target was temporally displaced by experimental intervention (computer editing of speech waveform), e.g., artificially extending by 100 msec a pre-stop-consonant silent interval two syllables earlier in the sentence. The result was interpreted in terms of disrupted timing expectancies based on distortion of the prosodic structure, i.e., an interaction between segmental and prosodic cue effects during ongoing perception. In further work, targets in six-syllable nonsense sequences were temporally displaced by lengthening or shortening one vowel in the sequence by various amounts (50–130 msec). The perceptual impression when noticeable is of a sudden shift in speech tempo. RT was measured to phoneme targets in over 600 sequences during several hours of listening. Despite practice and potential cue effects of pre-target manipulations, timing distortions within the first or second pretarget syllable slowed target RT. [Work supported by NIMH, ARIBSS.]