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Jean SCHOENTGEN


coordonnées


Ecole polytechnique de Bruxelles
Jean SCHOENTGEN
tel 02 650 36 60, fax 02 650 47 13, Jean.Schoentgen@ulb.ac.be
Campus du Solbosch
CP165/51, avenue F.D. Roosevelt 50, 1050 Bruxelles



unités de recherche


Traitement des Signaux (LIST/TS) [Signal Processing Group] (LIST/TS)



projets


ECLIPSE - Functional assessment of disordered voices and real-time monitoring under field conditions - Evaluation fonctionnelle clinique des pathologies vocales et suive embarqué [ECLIPSE - Functional assessment of disordered voices and real-time monitoring under field conditions]
The objective is the development of novel speech analysis methods that enable describing normal and pathological voices reliably and validly on the base of connected speech (as opposed to sustained vowels, which are the norm). High-speed imaging of the vibrating vocal folds is combined with acoustic analysis of sustained sounds to provide for clinical use multiple modalities that complement each other. The overall objective is the development of a clinical workstation running multiple analysis algorithms and the building of a portable device that enables monitoring speakers under field conditions. This project is a common project with the University of Mons and the Catholic University of Louvain. Cette recherche consiste à développer des nouvelles méthodes d'analyse du signal de parole permettant de caractériser de manière objective les voix pathologiques. Les techniques sont applicables à la parole continue contrairement aux méthodes actuelles qui sont limitées à l'analyse des voyelles soutenues. En parallèle, un traitement d'images des cordes vocales, prises par caméra haute vitesse, est mis à profit pour mettre en place une analyse multimodale et d'en d'améliorer l'efficacité. L'objectif global du projet est de développer une station de travail clinique incluant les logiciels d'analyse dédiés ainsi que la réalisation d'un dispositif portable permettant un suivi en continu des locuteurs à risque. Ce projet est réalisé en collaboration avec l'Université de Mons et l'Université Catholique de Louvain. [The objective is the development of novel speech analysis methods that enable describing normal and pathological voices reliably and validly on the base of connected speech (as opposed to sustained vowels, which are the norm). High-speed imaging of the vibrating vocal folds is combined with acoustic analysis of sustained sounds to provide for clinical use multiple modalities that complement each other. The overall objective is the development of a clinical workstation running multiple analysis algorithms and the building of a portable device that enables monitoring speakers under field conditions. This project is a common project with the University of Mons and the Catholic University of Louvain.]

Analysis of vocal tremor - Analyse du tremblement vocal [Analysis of vocal tremor]
The objective of the project is to analyse and describe vocal tremor in normophonic and dysphonic subjects. Vocal tremor is a modulation of the vocal frequency in an interval from 1 to 15 Hz. The estimation of the tremor frequency and depth is based on an algorithm that obtains the instants of glottal closure from the speech signal without an a priori knowledge of the average vocal frequency. Speech tremor owing to tremor of the articulators is estimated via the speech formants. The analysis is applied to normal subjects and speakers suffereing from Parkinson's disease, amyotrophic lateral sclerosis and vocal fatigue. Au cours de ce projet, nous étudions et quantifions les différentes composantes du tremblement vocal, à la fois chez des sujets normophoniques et dysphoniques. Pour étudier le tremblement dû à la source vocale, on développe un algorithme de mesure des caractéristiques du bruit de modulation en fréquence du signal de parole. Pour étudier le tremblement dû au conduit vocal, on développe des algorithmes de mesure de la fréquence des formants et des caractéristiques de variation de ceux-ci. Ces méthodes sont testées sur des signaux synthétiques, ainsi que sur des signaux réels, de sujets normaux et pathologiques. [The objective of the project is to analyse and describe vocal tremor in normophonic and dysphonic subjects. Vocal tremor is a modulation of the vocal frequency in an interval from 1 to 15 Hz. The estimation of the tremor frequency and depth is based on an algorithm that obtains the instants of glottal closure from the speech signal without an a priori knowledge of the average vocal frequency. Speech tremor owing to tremor of the articulators is estimated via the speech formants. The analysis is applied to normal subjects and speakers suffereing from Parkinson's disease, amyotrophic lateral sclerosis and vocal fatigue. ]

Synthesis of disordered voices - Synthèse des troubles de la voix [Synthesis of disordered voices]
The objective is the development of a synthesiser that simulates disordered voices. The synthesiser comprises a nonlinear model of the evolving glottal area, an aerodynamic model of the glottis and models of the wave propagation in the vocal tract and trachea. The simulated disorders are vocal jitter and shimmer, vocal frequency and amplitude tremor, diplophonia, biphonation, random cycles, additive noise owing to turbulence as well as asthenia and strain. Medical applications of the synthesis of voice disorders are the discovery of the acoustic cues of disordered voice timbres, the training of speech therapy students in the rating of disordered voices and the testing as well as calibration of acoustic analysis methods for the functional assessment of voice. L'objectif du travail est le développement d'un synthétiseur vocal en vue de la simulation des troubles de la voix. Le synthétiseur comporte un modèle numérique de la source vocale et du conduit vocal. Les perturbations simulées sont les microperturbations de cycle-à-cycle des durées et amplitudes des cycles vocaux de parole, ainsi que le tremblement vocal. D'autre types de troubles simulés sont la diplophonie, la bi-phonation et les irrégularités des cycles vocaux dues aux vibrations aléatoires des plis vocaux, ainsi que le souffle et l'asthénie ou le forçage. Les applications médicales de la synthèse vocale sont les expériences perceptuelles cliniques, la formation des cliniciens débutant, le calibrage des algorithmes d'analyses des dispériodicités vocales ainsi que la synthèse des points d'ancrage perceptifs pour les jurys d'écoute. [The objective is the development of a synthesiser that simulates disordered voices. The synthesiser comprises a nonlinear model of the evolving glottal area, an aerodynamic model of the glottis and models of the wave propagation in the vocal tract and trachea. The simulated disorders are vocal jitter and shimmer, vocal frequency and amplitude tremor, diplophonia, biphonation, random cycles, additive noise owing to turbulence as well as asthenia and strain. Medical applications of the synthesis of voice disorders are the discovery of the acoustic cues of disordered voice timbres, the training of speech therapy students in the rating of disordered voices and the testing as well as calibration of acoustic analysis methods for the functional assessment of voice. ]

Acoustic-to-articulatory mapping - Inversion acoustico-articulatoire [Acoustic-to-articulatory mapping]
Acoustic-to-articulatory mapping is the inference from the speech signal of the vocal tract shape from the glottis to the lips. A first method has consisted in recovering the vocal tract shape by means of the formant frequencies and constraints at the lips. A second method involves the inference of the vocal tract shape based on a simulation of the speech spectrum, anti-formants, sources and losses included. The objectives are the extraction of the formant frequencies by means of the inferred tract shapes as well as the representation of the speech signal in terms of morphological rather than acoustic features. L'inversion acoustico-articulatoire consiste à retrouver la forme du conduit vocal, depuis les cordes vocales jusqu'aux lèvres, à partir du signal acoustique. Une première étude a concerné la reconstruction de la fonction d'aire du conduit à partie de la connaissance des fréquences des premiers formants, en ajoutant éventuellement une contrainte sur l'ouverture aux lèvres. Une deuxième approche est basée sur une modélisation globale du spectre incluant également l'effet des anti-formants ainsi que de la source et des pertes. Les objectifs sont l'extraction des fréquences des formants ainsi que la représentation du signal de parole en termes d'indices morphologiques plutôt qu'acoustiques. [Acoustic-to-articulatory mapping is the inference from the speech signal of the vocal tract shape from the glottis to the lips. A first method has consisted in recovering the vocal tract shape by means of the formant frequencies and constraints at the lips. A second method involves the inference of the vocal tract shape based on a simulation of the speech spectrum, anti-formants, sources and losses included. The objectives are the extraction of the formant frequencies by means of the inferred tract shapes as well as the representation of the speech signal in terms of morphological rather than acoustic features.]

Speech Signal Analysis for Voice Disorders Characterization - Analyse du signal de parole pour la caractérisation des troubles de la voix [Speech Signal Analysis for Voice Disorders Characterization]
The analysis of speech is often involved in the evaluation of voice and the discrimination between disphonic and normophonic speakers. Most of the time, acoustic features of voice disorders are obtained from sustained vowels. However, sustaining speech sounds is considered to be less informative than speaking continuously. The objective of the project therefore is to monitor the voice timbre and vocal perturbations in connected speech. Vocal disperiodicities obtained are summarised by means of vocal features that report speech properties that are clinically relevant with regard to the assessment of a speaker's voice. The description of voice disorders owing to peripheral causes are also considered. L'analyse acoustique du signal de parole est souvent utilisée dans l'évaluation et la discrimination des voix pathologiques. Les mesures acoustiques utilisées pour caractériser les troubles de la voix sont extraites de voyelles soutenues. Cependant, la représentation basée sur les voyelles soutenues n'est pas toujours valide. L'estimation de paramètres à partir de la parole connectée semble plus adéquate. L'objectif de ce projet est le développement de méthodes permettant le suivi d'un locuteur au cours de la lecture d'un texte de longue durée. L'utilisation de méthodes applicables à des signaux non stationnaires est aussi envisagée. Le bruit estimé par les différentes méthodes permet de déterminer les indices pertinents utilisés dans la caractérisation des troubles de la voix du locuteur. La caractérisation de certains troubles vocaux dus à un problème neurologique périphérique, comme les voix dysarthriques, est aussi examinée. [The analysis of speech is often involved in the evaluation of voice and the discrimination between disphonic and normophonic speakers. Most of the time, acoustic features of voice disorders are obtained from sustained vowels. However, sustaining speech sounds is considered to be less informative than speaking continuously. The objective of the project therefore is to monitor the voice timbre and vocal perturbations in connected speech. Vocal disperiodicities obtained are summarised by means of vocal features that report speech properties that are clinically relevant with regard to the assessment of a speaker's voice. The description of voice disorders owing to peripheral causes are also considered. ]

ASPI - Audiovisual to Articulatory Speech Inversion. European FET Project. [ASPI - Audiovisual to Articulatory Speech Inversion. European FET Project.]
ASPI has been an European FET project involving LORIA (France), KTH (Sweden), TUA (Greece), ENST (France) and ULB (Belgium). Audiovisual-to-articulatory inversion consists in recovering the vocal tract shape (from the vocal folds to the lips) dynamics from the acoustical speech signal, supplemented by image analysis of the speaker's face. The design of audiovisual-to-articulatory inversion involves two kinds of interdependent tasks. The first is the development of inversion methods that successfully answer the main acknowledged difficulties (non-unicity of inverse solution, a possible lack of phonetic relevancy of inverse solutions, impossibility of using standard spectral data), and the second is the construction of an articulatory database that comprises dynamic images of the vocal tract together with the speech signal uttered, and that for several male and female speakers. [ASPI has been an European FET project involving LORIA (France), KTH (Sweden), TUA (Greece), ENST (France) and ULB (Belgium). Audiovisual-to-articulatory inversion consists in recovering the vocal tract shape (from the vocal folds to the lips) dynamics from the acoustical speech signal, supplemented by image analysis of the speaker's face. The design of audiovisual-to-articulatory inversion involves two kinds of interdependent tasks. The first is the development of inversion methods that successfully answer the main acknowledged difficulties (non-unicity of inverse solution, a possible lack of phonetic relevancy of inverse solutions, impossibility of using standard spectral data), and the second is the construction of an articulatory database that comprises dynamic images of the vocal tract together with the speech signal uttered, and that for several male and female speakers. ]



disciplines et mots clés déclarés


Electromagnétisme - analyse du signal Informatique médicale Ingénierie biomédicale Phonétique Sciences de l'ingénieur

analyse de la parole analyse en ondelettes analyse multimodale bruit vocal conduit vocal dispositif portable inversion acoustique inversion audiovisuelle maladie de parkinson signal de parole signaux non stationnaires simulations numérique source vocale synthèse de la parole traitement du signal traitement du signal de parole tremblement vocal troubles de la voix voix pathologiques