Subglottal coupling and vowel space

Abstract

A model of acoustic coupling between the oral and subglottal cavities predicts discontinuities in vowel formant prominences near resonances of the subglottal system. One discontinuity occurs near 1300–1500 Hz, suggesting the hypothesis that this is a quantal effect [K. N. Stevens, J. Phonetics 17, 3–46 (1989)] dividing speakers’ front and back vowels. Recordings of English vowels (in /hVd/ environments) for several male and female speakers were made, while an accelerometer attached to the neck area was used to capture the subglottal waveform. Statistics on our subglottal resonance measurements are given and compared with prior work. Qualitative agreement is shown between the resonator model and diphthong data with time-varying F2 for several speakers. Comparison of the second vowel formant and second subglottal formant tracks across all speakers, analysis of the formant spaces spanned by each speaker’s vowel data, and a survey of vowel formant data for a sample of the world’s languages support the possibility that a speaker’s second subglottal resonance divides front and back vowels. Possible implications for theories of vowel inventory structure [e.g., J. Lijencrants and B. Lindblom, Language 48, 839–862 (1972)] are discussed. [Work supported by NIH Grant DC00075.]