The influence of consonant environment on duration of vowels in the speech of normal hearing, moderately hearing impaired, and deaf adults

Abstract

The present study investigated the effect of consonant environment on the duration of vowels in the speech of ten normal hearing, ten moderately hearing impaired, and ten profoundly deaf adult males. Each subject uttered randomizations of eight CVC nonsense syllables consisting of the vowels /i/ and /α/, and the consonants /p/, /b/, /s/, and /z/. The moderately hearing impaired and deaf subjects all had adequate speech to perform the required verbal tasks. Each CVC sample was recorded on a tape recorder and was then individually played into a Honeywell visicorder which produced an audio wave. The duration of the vowels in the voiced/voiceless and plosive/fricative environments were measured in milliseconds from the oscillographic recordings. Results indicated that for the normal-hearing and moderately hearing impaired subjects, a significant difference in vowel duration occurred between the voiced/voiceless and between the plosive/fricative consonant environments. For the deaf subjects, there was no significant difference in vowel duration for any of the consonant environments.