Physical modeling of vowel-bilabial plosive sound production

Downstream of the vocal folds, it is often assumed that all the kinetic energy of the glottal jet is dissipated by turbulence. Although this assumption is reasonable for normal voicing, there are many configurations for which a constriction or even an occlusion of the vocal tract occurs and leads to a significant pressure recovery. Such a phenomenon occurs during the production of vowel-bilabial plosive sequences. In this paper, we will first present results from measurements on a human speaker during production of vowel-bilabial plosive-vowel sequences. These measurements concern intra-oral pressure, acoustical pressure, EGG and lips video recording of a female subject. The relative timings between the motion of the lips, the glottal signals and the intra-oral pressure are analyzed and related with Voice Onset/Offset Times. A theoretical model for air flow in the lips is validated by experiments on a mechanical replica of the vocal tract including a self-oscillating glottis and a controlled moving constriction to mimic the closure of the lips. This theoretical model is used to achieve numerical simulations of an /apa / utterance. The differences between the intra-oral pressure observed in vivo and the simulated one lead to an investigation on the influence of the cheeks expansion during bilabial plosive production. hal-00700404, version 1- 22 May 2012

Compensation strategies for a lip-tube perturbation of French [u]: an acoustic and perceptual study of 4-year-old children

Suggested running head: Compensation for a lip-tube perturbationCompensation for a lip-tube perturbation 2 The relations between production and perception in 4-year-old children were examined in a study of compensation strategies for a lip-tube perturbation. Acoustic and perceptual analyses of the rounded vowel [u] produced by twelve 4-year-old French speakers were conducted under two conditions: normal and with a 15-mm-diameter tube inserted between the lips. Recordings of isolated vowels were made in the normal condition before any perturbation (N1), immediately upon insertion of the tube and for the next 19 trials in this perturbed condition, with (P2) or without articulatory instructions (P1), and in the normal condition after the perturbed trials (N2). hal-00333668, version 1- 23 Oct 2008 The results of the acoustic analyses reveal speaker-dependent alterations of F1, F2, and/or F0 in the perturbed conditions and after the removal of the tube. For some subjects, the presence of the tube resulted in very little change; for others, an increase in F2 was observed in P1, which was generally reduced in some of the 20 repetitions, but not systematically and not continuously. The use of articulatory instructions provided in the P2 condition was detrimental to the achievemen