Localization and Selection of Speaker Specific Information with Statistical Modeling

International audienceStatistical modeling of the speech signal has been widely used in speaker recognition. The performance obtained with this type of modeling is excellent in laboratories but decreases dramatically for telephone or noisy speech. Moreover, it is difficult to know which piece of information is taken into account by the system. In order to solve this problem and to improve the current systems, a better understanding of the nature of the information used by statistical methods is needed. This knowledge should allow to select only the relevant information or to add new sources of information. The first part of this paper presents experiments that aim at localizing the most useful acoustic events for speaker recognition. The relation between the discriminant ability and the speech's events nature is studied. Particularly, the phonetic content, the signal stability and the frequency domain are explored. Finally, the potential of dynamic information contained in the relation between a frame and its p neighbours is investigated. In the second part, the authors suggest a new selection procedure designed to select the pertinent features. Conventional feature selection techniques (ascendant selection, knockout) allow only global and a posteriori knowledge about the relevance of an information source. However, some speech clusters may be very efficient to recognize a particular speaker, whereas they can be non informative for another one. Moreover, some information classes may be corrupted or even missing for particular recording conditions. This necessity fo

Analyse par bandes de fréquences pour la détection des zones de « déviance » dans la parole dysarthrique

International audienceCe travail s'inscrit dans le projet ANR DesPho-APaDy dont l'un des objectifs vise à décrire les caractéristiques phonético-acoustiques de la parole dysarthrique par le biais d'une approche combinant des procédures analy-tiques manuelles et des procédures issues du traitement automatique de la parole

Have a Cake and Eat it Too: Assessing Discrimination Performance of an Intelligibility Index Obtained from a Reduced Sample Size

International audienceThis paper investigates random vs. phonetically motivated reduction of linguistic material used in an intelligibility task in speech disordered populations and the subsequent impact on the discrimination classifier quantified by the area under the receiver operating characteristics curve (AUC of ROC). The comparison of obtained accuracy indexes shows that when the sample size is reduced based on a phonetic criterium-here, related to phonotactic complexity-, the classifier has a higher ranking ability than when the linguistic material is arbitrarily reduced. Crucially, downsizing the linguistic sample to about 30% of the original dataset does not diminish the discriminatory performance of the classifier. This result is of significant interest to both clinicians and patients as it validates a tool that is both reliable and efficient

Value of fetal autopsy after medical termination of pregnancy

http://www.sciencedirect.com/science/journal/03790738International audienceWe carried out a retrospective study of 352 medical terminations of pregnancy (MTP) carried out in a large French administrative region over two consecutive years. We analysed the indications for MTP and then compared the prenatal ultrasound diagnosis with fetal autopsy findings in order to demonstrate the value of pathological examination of the fetus in prenatal diagnosis and genetic counselling as well as the need to check by autopsy the quality of ultrasound screening. Preliminary analysis of the indication for these MTP showed that in 69.9% ultrasound screening had been carried out, revealing mainly brain abnormalities (22.2%) and heart defects generally associated with chromosomal abnormalities (32.1%). Prenatal findings were in agreement with autopsy results, showing no false-positive prenatal diagnoses. However, in 7.9% of cases in which brain abnormalities were detected, confirmation was not possible at autopsy because of tissue autolysis, showing the need for optimal conditions of expulsion. In 35.8% of cases, confirmation of the diagnosis by autopsy was not useful for management but still added to medical knowledge and demonstrated to the mother the reality of the defects. In 50.9%, the autopsy findingswere decisive for genetic counselling

Value of fetal autopsy after medical termination of pregnancy

http://www.sciencedirect.com/science/journal/03790738International audienceWe carried out a retrospective study of 352 medical terminations of pregnancy (MTP) carried out in a large French administrative region over two consecutive years. We analysed the indications for MTP and then compared the prenatal ultrasound diagnosis with fetal autopsy findings in order to demonstrate the value of pathological examination of the fetus in prenatal diagnosis and genetic counselling as well as the need to check by autopsy the quality of ultrasound screening. Preliminary analysis of the indication for these MTP showed that in 69.9% ultrasound screening had been carried out, revealing mainly brain abnormalities (22.2%) and heart defects generally associated with chromosomal abnormalities (32.1%). Prenatal findings were in agreement with autopsy results, showing no false-positive prenatal diagnoses. However, in 7.9% of cases in which brain abnormalities were detected, confirmation was not possible at autopsy because of tissue autolysis, showing the need for optimal conditions of expulsion. In 35.8% of cases, confirmation of the diagnosis by autopsy was not useful for management but still added to medical knowledge and demonstrated to the mother the reality of the defects. In 50.9%, the autopsy findingswere decisive for genetic counselling