ABSTRACT
The durations of speech segments are known to be influenced by several factors. The most important of these are probably the intrinsic durations of the component phonemes, the stress on each syllable, and some phrasal effects, such as phrase-final lengthening. Similarities between effects at different linguistic levels suggest that speech timing rules may be hierarchically organized. Despite this fairly detailed knowledge of timing regularities, little is known about how critical correct timing is for intelligibility. An experiment is described that measured the intelligibility of sentences synthesized by rule. The results show that assigning an incorrect fundamental frequency contour reduced intelligibility to about two-thirds of its value with correct fundamental, and that incorrect timing had an even more dramatic effect, reducing intelligibility to about one-third of its “normal” value. There are obvious implications for speech training of the deaf.
