Acoustic and Perceptual Properties of Syllables in Continuous Speech as a Function of Speaking Rate

Fifteen short sentences spoken by four male speakers have been used as the test material. Each speaker has been asked to pronounce the sentences with three different rates: fast, normal, and slow. For perceptual experiment, two kinds of segmentations have been made: 1) one-syllable segmentation and 2) two-syllable segmentation. In the one-syllable segmentation, individual CV-syllables have been taken out from their contexts and presented to listeners. In the two-syllable segmentation, every consecutive two syllables have been isolated from the running speech, and the listeners have to identify each of the two syllables. In the first experiment, the results reveal that individual syllables do not have enough phonetic information to be correctly identified especially for the fast speech. The average identification of syllables for the fast speech is 35% and even vowels are identified less than 60%. In the second experiment, however, syllable identifications rose to a certain extent: for the fast speech, 54% for the first syllable and 73% for the second syllable. For the normal speech, they were 50% and 88%, respectively and for the slow speech, they were 56% and 90% respectively.