Effects of Timing Regularity and Metrical Expectancy on Spoken-Word Perception

Abstract

Certain types of speech, e.g. lists of words or numbers, are usually spoken withhighly regular inter-stress timing. The main hypothesis of this study (derived fromthe Dynamic Attending Theory) is that listeners attend in particular to speech eventsat these regular time points. Better timing regularity should improve spoken-wordperception. Previous studies have suggested only a weak effect of speech rhythm onspoken-word perception, but the timing of inter-stress intervals was not controlledin these studies. A phoneme monitoring experiment is reported, in which listenersheard lists of disyllabic words in which the timing of the stressed vowels was eitherregular (with equidistant inter-stress intervals) or irregular. In addition, metricalexpectancy was controlled by varying the stress pattern of the target word, as eitherthe same or the opposite of the stress pattern in its preceding words. Resulting reac-tiontimes show a main effect of timing regularity, but not of metrical expectancy.These results suggest that listeners employ attentional rhythms in spoken-word per-ception,and that regular speech timing improves speech communication.