Intrinsic vowel duration and formant frequencies: Data from speech acquisition

Abstract

The vowels of American English are specified by particular formant frequency patterns and durations. Acoustic data derived from the speech of children between the ages of 69 and 145 weeks show that the vowels that they produce in meaningful words often have mismatched formant frequency patterns and durations. The formant frequency pattern of an intended [i], for example, may have the duration of an [1]. Psychoacoustic experiments using computer edited stimuli derived from the children's vowel productions demonstrate the interaction of formant frequency patterns and duration as acoustic cues to vowel perception. Intrinsic vowel duration and control of the supralaryngeal vocal tract appear to be independent parameters in the acquisition of speech. Hypothetical phonetic features like Tenseness thus can not be causally linked to relative vowel duration.