Rhythmic organization of read word lists

Abstract

Rhythmic constraints have been notoriously hard to identify in speech timing. Appropriate experimental tasks may help in identifying grouping principles and timing constraints. In a baseline experiment, subjects read wordlists which contained eight trochees. They were instructed to read the words with regular timing. The inter–onset intervals obtained show evidence of a binary grouping into ‘‘feet’’ containing two words each, and of two-word feet grouping into 4-word super-feet. Results were consistent with a hierarchical rhythm grouping of units into pairs, with the second element of each such group exhibiting some degree of deceleration or final lengthening. In a second condition, each word list contained 7 trochees and one (list medial) iamb. Inter–onset intervals suggest that a similar grouping takes place, with the stressed syllable of the iamb, rather than the first syllable, marking the onset of a unit. In a third condition, the iamb was preceded by a dactyl, giving a 4-syllable foot. Again, results suggest that the stressed syllables, rather than word onsets, delimit production units. Together the results suggest that the stress foot is a unit which serves to structure speech in time.