3 research outputs found
Using phonetic constraints in acoustic-to-articulatory inversion
The goal of this work is to recover articulatory information from the speech
signal by acoustic-to-articulatory inversion. One of the main difficulties with
inversion is that the problem is underdetermined and inversion methods
generally offer no guarantee on the phonetical realism of the inverse
solutions. A way to adress this issue is to use additional phonetic
constraints. Knowledge of the phonetic caracteristics of French vowels enable
the derivation of reasonable articulatory domains in the space of Maeda
parameters: given the formants frequencies (F1,F2,F3) of a speech sample, and
thus the vowel identity, an "ideal" articulatory domain can be derived. The
space of formants frequencies is partitioned into vowels, using either
speaker-specific data or generic information on formants. Then, to each
articulatory vector can be associated a phonetic score varying with the
distance to the "ideal domain" associated with the corresponding vowel.
Inversion experiments were conducted on isolated vowels and vowel-to-vowel
transitions. Articulatory parameters were compared with those obtained without
using these constraints and those measured from X-ray data
Perception auditive, visuelle et audiovisuelle des voyelles nasales par les adultes devenus sourds. Lecture labiale, implant cochléaire, implant du tronc cérébral.
This thesis focuses on the visual, auditory and auditory-visual perception of french nasal vowels [ɑ̃](« lent »), [ɔ̃] (« long ») and [ɛ̃] (« lin ») by Cochlear Implant (CI) and Auditory Brainstem Implant(ABI) adults users. The study on visual perception of vowels, with 22 deafened adults, redefines thelip configuration of french nasal vowels and provides an update of the classification of vocalic visualphonemes. Three studies on auditory identification of nasal vowels with 82, 15 and 10 CI usershighlight their difficulty in recognizing the three nasal vowels, which they perceive as oral vowels.Acoustic and perceptual analyzes suggest that adults with CI rely on frequency informations of thefirst two spectral peaks but miss the informations of relative intensity of these peaks. The study with13 ABI users show that some linguistic acoustic cues are transmitted by the ABI but the fusion ofauditory and visual features could be optimized for the identification of vowels. Finally, a survey of179 Speech Language and Hearing Therapists show the need of an update on the phonetic articulationof french nasal vowels [ɑ̃] and [ɛ̃].Cette thèse porte sur la perception visuelle, auditive et audiovisuelle des voyelles nasales [ɑ̃] (« lent »),[ɔ̃] (« long ») et [ɛ̃] (« lin ») par des adultes devenus sourds, implantés cochléaires et implantés dutronc cérébral. L’étude sur la perception visuelle des voyelles, auprès de 22 adultes devenus sourds,redéfinit les sosies labiaux des voyelles nasales et propose une mise à jour de la classification desvisèmes. Trois études sur l’identification auditive des voyelles nasales auprès de 82, 15 et 10 adultesimplantés cochléaires mettent en évidence leur difficulté à reconnaitre les trois voyelles nasales, qu’ilsperçoivent comme des voyelles orales. Les analyses acoustiques et perceptives suggèrent que lesadultes implantés cochléaires s’appuient sur les informations fréquentielles des deux premiers picsspectraux mais négligent les informations d’intensité relative de ces pics. D’après l’étude menéeauprès de 13 adultes implantés du tronc cérébral, des informations acoustiques linguistiques sonttransmises par l’implant du tronc cérébral mais la fusion entre les informations auditives et visuellespourrait être optimisée pour l’identification des voyelles. Enfin, une enquête auprès de 179orthophonistes pointe le besoin d’une information sur la définition phonétique articulatoire actualiséedes voyelles [ɑ̃] et [ɛ̃]