Vowel duration in the speech of hearing and deaf children

Abstract

The duration of vowels in five sentences as read by 16 deaf and 16 hearing children, and one deaf adult, were measured using a computerized, visually assisted, auditory segmentation technique. Data were obtained on absolute and relative durations of vowels with respect to type, the tense-lax feature, lexical stress, and prepausal and sentence-final lengthening. On each sentence, the duration pattern was quantified in terms of the ratios of the durations of successive pairs of vowels. The relationship between the various duration measures and intelligibility was examined. Hearing children produced absolute and relative durations analogous to those reported previously for adults. Deaf subjects produced absolute durations which were two to three times those of the hearing group. However, they also produced relative durations which conformed to normal patterns associated with vowel type, the tense-lax feature, lexical stress, and sentence pattern. Relative duration was closely correlated with intelligibility, but absolute duration was not. Implications for speech training programs for the deaf are discussed. [Work supported by NINCDS.]