A Study of Syllabic Stress in Some English Words as Produced By Deaf and Normally Hearing Speakers

The aim of this investigation was to compare the syllable stress production of deaf and normally hearing speakers. Ten orally-trained deaf speakers and forty normally hearing speakers recorded six pairs of bisyllabic words which were either nouns or verb-adjectives depending upon the placement of primary stress. Syllabic differences in intensity, duration, and fundamental frequency were measured. In addition, a panel of expert listeners made judgments on which syllable had been given primary stress. Most (81%) of the words spoken by the hearing subjects were correctly judged , regarding the placement of primary stress, while relatively few (20%) of the words spoken by the deaf were judged correctly. Usually, greater intensity, longer duration, and higher fundamental frequency characterized the correctly identified primary syllable stress produced by both the hearing and the deaf subjects. However, in some instances all three acoustic cues were not necessary for the correct recognition of primary stress. Higher fundamental frequency was always present in the primary stressed syllable of correctly recognized nouns. Greater intensity and/or longer duration characterized the stressed syllables of correctly recognized verb-adjectives. Despite the presence of all three acoustic cues, some words spoken by the deaf subjects were not correctly identified. Inspection of spectrographic recordings suggested that these failures may have been due to lack of falling inflection on the initial syllable of nouns, inability to produce schwa vowels in verb-adjectives, and inappropriate and excessively long junctures between syllables.