ASA 127th Meeting M.I.T. 1994 June 6-10

2pSP26. Influence of the vocal effort on vowels.

Maria-Gabriella Di Benedetto

Dept. INFOCOM, Universita degli Studi di Roma ``La Sapienza,'' via Eudossiana 18, 00184 Rome, Italy

Jean-Sylvain Lienard

LIMSI-CNRS, 91403 Orsay Cedex, France

Vocal effort is one of the less studied sources of speech variability. An investigation of its effects on French vowels was carried out. Twelve French vowels uttered in isolation by 13 speakers, 7 females and 6 males, were recorded. The subject was instructed to repeat the vowel pronounced by the operator with three degrees of vocal effort induced by the distance between the speaker and the operator (30 cm and 1.5 and 7 m); the variations kept within the interval encountered in the usual living conditions, far from the whispered or shouted types of voice. Some of the speakers were recorded twice, 6 months apart. The resulting 720 tokens were assessed by a separate group of listeners who judged vowel identity, perceived speaker's gender, and perceived vocal effort. Results of acoustic analysis show a change in the global slope of the spectrum and a significant increase of the F1 frequency correlated with the degree of vocal effort, with some dependency on the particular vowel and speaker. The average increase is about 50 Hz between the two extreme speaking conditions, corresponding to an interval of about 12 dB in the overall level. [Work supported by a CNRS-CNR cooperation.]