Laryngeal Behavior in Whispered Voice: a study using high speed imaging

International audienceIntroduction: Whispered voice is characterized by the lack of voicing and the presence of friction noise except during the closed phase of plosives. However, segmental contrasts such as voicing tend to be preserved in whispered speech. Acoustic and perceptual studies have showed that formant frequencies and intensity were some of the phonetic parameters that allow the listeners to distinguish the voicing feature between normal and whispered modes. The aim of our study is to compare the laryngeal behaviour of whispered voice at the level of the glottis and of the supraglottic region using high speed imaging in 2 situations, voiced and unvoiced consonants and vowel production. Methods: Our preliminary study consists in measuring the glottic area and the supra glottic involvement during syllables VCV and CVC with V = /i/ and C = labial fricatives /f/ and /v/ as uttered by 3 male and 3 female subjects. We used a fiberscope (Pentax) and a rigid scope using the High Speed Camera Weinberger "SpeedCam Lite" (500 i/sec) and the Wolf Endocam (4000i/sec). Results: When whispering, the supraglottic constriction varies with the voicing feature of the consonant. Whispered segments have an anterior-posterior and a transversal compression between the arytenoids, the aryepiglottic folds and the base of the epiglottis. Conclusions: The paper discusses how far the voiced and the unvoiced consonants and the vowels uttered with a lack of vibrations of the vocal folds accompanied with an open glottis, and is there too a supraglottic constriction (aryepiglottic constriction mechanism)