Vowel Duration in Whispered and in Normal Speech

Vowel duration measurements were made from the sound spectrographic patterns of normal and whispered consonant-vowel-consonant syllables produced by three male speakers. It was found that the average duration of whispered vowels was longer than that of normal vowels. Like normal vowels, whispered vowels can be grouped according to four degrees of length: long—/æ, α, o/, relatively long—/e, ε, o/, relatively short—/i, u/, and short—/i, ε, A, U/. Like normal vowels, whispered vowels increase in duration with degree of mouth opening, if tense and lax vowels are considered separately, tense whispered vowels are longer than lax whispered vowels, and whispered vowels are longer preceding voiced consonants and fricative consonants than they are preceding voiceless consonants and stop consonants. An attempt is made to explain vowel duration variations in terms of language structure and the dynamic properties of the speech mechanism.