L’analyse des signaux de parole permet de comprendre le fonctionnement de l’appareil vocal, mais aussi de décrire de nouveaux paramètres permettant de qualifier et quantifier la perception de la voix. Dans le cas de la parole expressive, l'intérêt se porte sur des variations importantes de qualité vocales et sur leurs liens avec l’expressivité et l’intention du sujet. Afin de décrire ces liens, il convient de pouvoir estimer les paramètres du modèle de production mais aussi de décomposer le signal vocal en chacune des parties qui contribuent à ce modèle. Le travail réalisé au cours de cette thèse s’axe donc autour de la segmentation et la décomposition des signaux vocaux et de l’estimation des paramètres du modèle de production vocale : Tout d’abord, la décomposition multi-échelles des signaux vocaux est abordée. En reprenant la méthode LoMA qui trace des lignes suivant les amplitudes maximum sur les réponses temporelles au banc de filtre en ondelettes, il est possible d’y détecter un certain nombre de caractéristiques du signal vocal : les instants de fermeture glottique, l’énergie associée à chaque cycle ainsi que sa distribution spectrale, le quotient ouvert du cycle glottique (par l’observation du retard de phase du premier harmonique). Cette méthode est ensuite testée sur des signaux synthétiques et réels. Puis, la décomposition harmonique + bruit des signaux vocaux est abordée. Une méthode existante (PAPD - Périodic/APériodic Décomposition) est adaptée aux variations de fréquence fondamentale par le biais de la variation dynamique de la taille de la fenêtre d’analyse et est appelée PAP-A. Cette nouvelle méthode est ensuite testée sur une base de signaux synthétiques. La sensibilité à la précision d’estimation de la fréquence fondamentale est notamment abordée. Les résultats montrent des décompositions de meilleures qualité pour PAP-A par rapport à PAPD. Ensuite, le problème de la déconvolution source/filtre est abordé. La séparation source/filtre par ZZT (zéros de la transformée en Z) est comparée aux méthodes usuelles à base de prédiction linéaire. La ZZT est utilisée pour estimer les paramètres du modèle de la source glottique via une méthode simple mais robuste qui permet une estimation conjointe de deux paramètres du débit glottique : le quotient ouvert et l'asymétrie. La méthode ainsi développée est testée et combinée à l’estimation du quotient ouvert par ondelettes. Finalement, ces trois méthodes d’estimations sont appliquées à un grand nombre de fichiers d’une base de données comportant différents styles d’élocution. Les résultats de cette analyse sont discutés afin de caractériser le lien entre style, valeur des paramètres de la production vocale et qualité vocale. On constate notamment l’émergence très nette de groupes de styles. / Analysis of speech signals is a good way of understanding how the voice is produced, but it is also important as a way of describing new parameters in order to define the perception of voice quality. This study focuses on expressive speech, where voice quality varies a lot and is explicitly linked to the expressivity or intention of the speaker. In order to define those links, one has to be able to estimate a high number of parameters of the speech production model, but also be able to decompose the speech signal into each parts that contributes to this model. The work presented in this thesis addresses the segmentation of speech signals, their decomposition and the estimation of the voice production model parameters. At first, multi-scale analysis of speech signals is studied. Using the LoMA method that traces lines across scales from one maximum to the other on the time domain response of a wavelet filter bank, it is possible to detect a number of features on voiced speech, namely : the glottal closing instants, the energy associated to each glottal cycle, the open quotient (by estimating the time delay of the first harmonic). This method is then tested on both synthetic and real speech. Secondly, harmonic plus noise decomposition of speech signals is studied. An existing method (PAPD standing for Periodic/Aperiodic Decomposition) is modified to dynamically adapt the analysis window length to the fundamental frequency (F0) of the signal. The new method is then tested on synthetic speech where the sensibility to the estimation error on F0 is also discussed. Decomposition on real speech, along with their audio files, are also discussed. Results shows that this new method provides better quality of decomposition. Thirdly, the problem of source/filter deconvolution is addressed. The ZZT (Zeros of the Z Transform) method is compared to classical methods based on linear prediction. ZZT is then used for the estimation of the glottal flow parameters with a simple but robust method based on the joint estimation of both the open quotient and the asymmetry. The later method is then combined to the estimation of the open quotient using wavelet analysis. Finally, the three estimation methods developed in this thesis are used to analyze a large number of files from a database presenting different speaking styles. Results are discussed in order to characterize the link between style, model parameters and voice quality. We especially notice the neat appearance of speaking style groups

Esta dissertação foi elaborada a partir de uma abordagem inter/transdisciplinar que compreende a Linguística Aplicada (LA), a Análise Dialógica do Discurso (ADD) e a Análise do Discurso de linha francesa (AD). A pesquisa desenvolvida teve como objetivo analisar como a experiência no exterior e a participação no Programa de Mobilidade Internacional (PMI) são discursivamente representadas pelos sujeitos quando ocupam o lugar discursivo de (futuros) professores de Língua Estrangeira (LE). Isso significa que buscamos investigar como a experiência vivenciada por esses sujeitos no exterior pode incidir em sua formação acadêmica e em sua prática profissional. Em relação aos participantes da pesquisa, analisamos como quatro (04) professores pré-serviço ou em-serviço de LEs (inglês e francês), que participaram do programa, representam o PMI, o contato com a LE no exterior e o processo de ensino/aprendizagem de LE. Depoimentos desses quatro professores foram coletados por meio da Proposta AREDA (Análise de Ressonâncias Discursivas em Depoimentos Abertos) (SERRANI-INFANTE, 1998). Como resultado, foi possível perceber que a relação dos participantes da pesquisa em relação à experiência vivenciada no PMI encontra-se balizada por três representações, assim denominadas: i) representando o PMI; ii) representando o contato com a LE no exterior; iii) representando o processo de ensino-aprendizagem de LE. Essas representações se interpenetram e se interconstituem, sendo que a discursividade construída nos dizeres dos enunciadores acena para algumas inscrições discursivas, a saber: i) a inscrição no PMI enquanto referencialidade para a formação do professor de LE e a inscrição na (ilusão) de completude (representando o PMI); ii) a inscrição no discurso da excelência e na completude do outro (representando o contato com a LE no exterior); iii) a inscrição no PMI enquanto referencialidade para o aprendizado e para o ensino (representando o processo de ensino-aprendizagem de LE). Assim, para enunciar sobre o lugar do PMI em sua formação acadêmica e em sua prática profissional, os professores se inscrevem discursivamente de forma a representar o PMI a partir do lugar sócio-histórico-ideológico-discursivo que ocupam. A dialogicidade instaurada entre as inscrições discursivas deixa vir á tona a tomada de posição desses sujeitos que constroem um lugar imaginário para o PMI, de forma a representá-lo discursivamente como essencial/fundamental para o ensino-aprendizagem da LE e para a formação e a prática do professor de LE, ou seja, há a inscrição no discurso da supremacia do PMI para a constituição do sujeito-professor de LE. / This thesis was elaborated from an inter/transdisciplinary approach that includes Applied Linguistics (AL), Dialogical Discourse Analysis (DDA) and French Line Discourse Analysis (DA). The developed research had as purpose to analyze how abroad experience and International Mobility Program (IMP) participation are discursively represented by the individuals when they occupy the discursive place of (future) Foreign Languages (FL) teachers. This means that we aim to investigate how the abroad experience faced by these individuals can influence their academic education and their professional practice. Regarding the research participants, we analyzed how four (04) pre-service or in-service FLs teachers (English and French) who participated in the program, representing IMP, contact with FL abroad and FL learning teaching process. These four teachers testimonials were collected through the AREDA Proposal (Analysis of Discursive Resonances in Open Testimonials) (SERRANI-INFANTE, 1998). As a result, it was possible to realize that the relation of the research participants in concerning to the experience faced in the IMP is marked by three representations, which are: i) representing IMP; ii) representing the contact with abroad FL; iii) representing FL teaching-learning process. These representations interpenetrate and interconstitute themselves, and the built discursiveness in some of enunciators sayings beckons for some discursive inscriptions, namely: i) the IMP inscription as reference for FL teacher formation and the inscription in the (illusion) of completeness (IMP representing); ii) excellence speech inscription and completeness of the other (representing the contact with the FL abroad); iii) enrollment in PMI as a reference for learning and teaching (representing the teaching-learning process of FL). Therefore, in order to place IPM influence in its academic education and in its professional practice, the teachers discursively register themselves in order to represent the IMP from the socio-historical-ideological-discursive place they occupy. The dialogue established by the discursive inscriptions reveals the positioning of those individuals who build an imaginary place for IMP, in order to represent it discursively as essential/fundamental for FL teaching and learning and for FL teacher formation and practice, in other words, there is an inscription in the IMP's supremacy discourse for FL teacher’s constitution. / Dissertação (Mestrado)

Within the context of the assessment of laryngeal function, acoustic analysis has an important place because the speech signal may be recorded non-invasively and it forms the base on which the perceptual assessment of voice is founded. Given the limitations of perceptual ratings, one has investigated vocal cues of disordered voices that are clinically relevant, summarize properties of speech signals and report on a speaker's phonation in general and voice in particular. Ideally, the acoustic descriptors should also be correlates of auditory-perceptual ratings of voice. Generally speaking, the goal of acoustic analysis is to document quantitatively the degree of severity of a voice disorder and monitor the evolution of the voice of dysphonic speakers.<p><p><p>The first part of this thesis is devoted to the analysis of disordered connected speech. The aim is to investigate vocal cues that are clinically relevant and correlated with auditory-perceptual ratings. Two approaches are investigated. The variogram-based method in the temporal domain is addressed first. The second approach is in the cepstral domain. In particular, the first rahmonic amplitude is used as an acoustic cue to describe voice quality. A multi-dimensional approach combining temporal and spectral aspects is also investigated. The goal is to check whether acoustic cues in both domains report complementary information when predicting perceptual scores.<p><p><p>Both methods are tested first on a corpus of synthetic sound stimuli that has been obtained by means of a synthesizer of disordered voices. The purpose is to learn about the link between the signal properties (fixed by the synthesis parameters) and acoustic cues.<p>In this study, we had the opportunity to use two large natural speech corpora. One of them has been perceptually rated. <p><p><p>The final part of the text is devoted to the automatic classification of voice with regard to perceived voice quality. Many studies have proposed a binary (normal/pathological) classification of voice samples. An automatic categorization according to perceived degrees of hoarseness appears, however, to be more attractive to both clinicians and technologists and more likely to be clinically relevant. Indeed, one way to reduce inter-rater variability of an auditory-perceptual evaluation is to ask several experts to participate and then to average the perceptual scores. However, auditory-perceptual evaluation of a corpus by several judges is a very laborious, time-consuming and costly task. Making this perceptual evaluation task automatic is therefore desirable. <p>The aim of this study is to exploit the support vector machine classifier that has become, over the last years, a popular tool for classification, to carry out categorization of voices according to perceived degrees of hoarseness. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

The thesis identifies and further examines the role of propaganda in the Russian-Ukrainian conflict, more specifically in the period around the annexation of the Crimean peninsula by the Russian Federation in March 2014. Critical discourse analysis is employed in order to analyse selected speeches of the President of the Russian Federation, Vladimir Putin, and the President of the United States of America, Barack Obama, relevant to the topic and in the period under investigation. The first chapter introduces a theoretical framework on propaganda in international relations, its definition, history and research. The methodology is described in detail in the second chapter. The historical context of the conflict is provided at the beginning of the empirical part of the thesis closely followed by a detailed analysis of the selected speeches. The findings support the prediction that there is a presence of propaganda identified within the speeches of both political leaders, thus in the conflict itself, and offer valuable insights into the hidden meanings and possible motives behind its use. The study advances our understanding of the phenomenon and helps us to expose and confront propaganda further.