L’objectif de la thèse a été d’étudier la structure, la fonction et la plasticité au cours du temps du chant d’un oiseau mâle adulte, la fauvette à tête noire Sylvia atricapilla. L’influence de différents comportements migratoires sur les caractéristiques du chant, sur la maintenance des dialectes et sur l’apprentissage a également été étudiée chez deux populations, une migratrice (représentée par 2 groupes à Paris) et une sédentaire (représentée par 3 groupes en Corse). Le chant de cette espèce est constitué de deux parties aux caractéristiques acoustiques bien distinctes, le warble et le whistle. Nos expériences de diffusion montrent que chacune des deux parties peut provoquer une réponse territoriale des mâles. Ce chant en deux parties permet probablement aux fauvettes de transmettre des informations différentes, destinées à différents auditoires, proches et lointains, mâles et femelles. Nos analyses génétiques par microsatellites ne montrent pas de structure génétique des groupes et populations. Néanmoins, nous avons montré l’existence de variations micro-géographiques au niveau de la composition en syllabes et en séquences de syllabes de cette seconde partie du chant. Bien que le renouvellement des individus soit plus important chez les migrateurs que chez les sédentaires, les 2 populations ont un taux de partage de syllabes et de phrases équivalent au sein des groupes. Nous avons cependant observé que les individus migrateurs ont un répertoire de syllabes 2 fois plus grand mais une diversité de phrases partagées 2 fois moins grandes que les sédentaires. Le suivi d’individus sédentaires sur plusieurs années consécutives a permis de montrer que l’espèce faisait preuve d’une plasticité vocale puisqu’on observe un plus grand partage de syllabes et de phrases intra année qu’inter année au sein des groupes. Même si les individus semblent modifier le contenu de leurs chants chaque année, nous n’avons pas réussi à mettre en évidence par des expériences de diffusion en milieu naturel un apprentissage à l’âge adulte de nouvelles syllabes ou de nouvelles phrases. / The aim of the thesis was to study the structure, function and plasticity over time of the song of a male adult bird, the blackcap Sylvia atricapilla. The influence of different migratory behaviors on the song characteristics, on the dialect maintenance and on learning has also been studied in two populations, a migratory one (represented by two groups in Paris) and a sedentary one (represented by 3 groups in Corsica). The song of this species consists of two parts with distinct sound characteristics, the warble and the whistle. Our playback experiments show that both parts trigger male territorial response. Such a song in two parts probably allows blackcaps to transmit different information for different audiences, close and distant, males and females. Genetic analyzes with microsatellites show no genetic structure of groups and populations. Nevertheless, we have shown the existence of micro-geographical variations in the composition of syllables and sequences of syllables in the whistle part. Although the turnover of individuals is higher among migrants than among sedentary populations, the two populations have similar syllables and phrases sharing within groups. However, migratory birds, compared to sedentary ones, have a syllable repertoire size twice as large and a repertoire of phrase sharing much smaller. The survey of sedentary individuals over several consecutive years has shown that the species show a vocal plasticity since a greater sharing of syllables and of phrases is observed intra year than between years within groups. Although individuals seem able to modify their songs every year, we didn’t succeed in showing with playback experiments in natural environment that adults males were able to learn new syllables or new phrases.

The English spoken in the United States has traditionally been divided into six dialect regions: New England, Mid-Atlantic, Southern, Midland, Northern, and Western. The acoustic properties of American English spoken in the Southern and Northern dialect regions have been the subject of intense research, but the acoustic properties of the Western dialect region have not been analyzed as thoroughly. The umbrella term, Western American English, includes the English spoken in a large geographic area that stretches from Montana, Wyoming, Colorado, and New Mexico to the Pacific coast. Research that has focused on the Western dialect has included participants from several states, which discounts the idea that smaller dialectical differences may exist within the West. This study describes several acoustic properties of American English as it is spoken in the state of Utah. Data collected from target hVd words were used to determine vowel formant frequency patterns using F1 and F2 values of monophthongal and diphthongal vowels, and calculate the vowel space area. Differences in vowel placement and vowel space area were found between the English spoken in Utah and the Northern, Southern, and Midland dialect regions. Similar to characteristics found in Western English, an analysis of the vowel productions in speakers from Utah indicated a fronted /ʊ/, as well as a near merger of /ɑ/ and /ɔ/. However, the analysis also revealed differences in Utah English when compared to the larger Western dialect region. In particular it was found that, unlike descriptions of Western English, Utah English speakers produced /æ/ with a relatively higher F1 than /ɑ/. The vowel space area of Utah English was found to be smaller than the vowel space area of Northern English, but larger than the vowel space area of Southern or Midland speakers.

The purpose of this study was to examine the correlation between acoustic and kinematic measures of diphthong production in 11 individuals with multiple sclerosis (MS) and 11 neurologically healthy control speakers. The participants produced four diphthongs: /ɔɪ/, /aʊ/, /aɪ/, /eɪ/. These sounds were spoken in a sentence context. Their speech audio signal was recorded with a microphone and their tongue movements were recorded with a magnetic tracking system. The first and second formants (F1 and F2) were computed with acoustic analysis software, and these signals were time-aligned with the vertical and anteroposterior magnet movement records. Pearson correlations between F1 and the magnet's vertical movement and between F2 and anteroposterior movement were computed for the individual diphthongs. The results of this study revealed an often non-linear relationship between the acoustic and kinematic measures. The degree to which the formant measures predicted the lingual movements varied across speakers and also during the on-glide, transition, and off-glide phases of the diphthongs. The findings of this study suggest that the relationship between formants and tongue movements is more complex than would be predicted from the theoretical origins of F1 and F2. Thus, researchers should be aware that acoustic parameters might not always accurately reflect the physical movements of articulators.

Contrastive stress is an aspect of communication that can be used to highlight information, de-accent redundant information, and create distinctions between new and previously-provided information. Previous research has documented that adult speakers use relative changes in their vocal intensity, fundamental frequency (F0), and duration to mark contrastive stress in a sentence. However, less is understood about how and when children mark contrastive stress in their communication, thus the current study aims to examine a number of acoustic elements of contrastive stress in 8 to 10-year-old children. Speech samples were elicited from 20 children and analyzed to determine if the acoustic parameters of F0, intensity, and duration varied as a function of the speaking condition, speaker gender, or grammatical unit. Results of the experiment suggest that when comparing the baseline speaking condition to the speaking condition eliciting contrastive stress, significant differences were only found for the acoustic measure of mean intensity. Additionally, gender-related differences in contrastive stress were found only for the dependent measure of F0 slope, with a greater F0 slope exhibited by female speakers. All grammatical units were significantly different from one another across a number of variables, with significant interactions between baseline and target conditions and grammatical unit being analyzed. As indicated in previous research, the findings of the present study may indicate that children under 10 years of age may not have developed contrastive stress in an adult-like manner. Results may also be due to individual speaker differences, the complex nature of prosody, or measurement methodology.

The Cettiidae, a family of primarily small, insectivorous, Asiatic and Austronesian, mountain birds have been the subject of acoustic analysis in the past. However, until this point, an in-depth review of the songs of the entire family had yet to be undertaken. In an effort to resolve this shortcoming, the songs of 29 Cettiidae species were examined through the usage of acoustic analysis software, with specific factors such as bandwidth, frequency, and strophe duration being statistically recorded. In total 286 individuals and over 800 strophes were analyzed, with the collected data being displayed in various PCA plots. These PCA graphs were then compared to both a dated phylogenetic tree specifically created for this study, and a Mahalanobis distance vs. genetic distance plot, created using the acoustic data as well as Cytochrome b genetic data. Based on these plots, several notable trends could be observed across the entire family. While largescale divergence from the norm was noted in several pairwise comparisons of species, as well as large scale conservation within clades such as the island Horornis species, examples of convergent evolution of their songs was rather scant. It was also noted that despite the strong divergence of certain species, each genus occupied its own area of multivariate space within the PCAs. Strong statistical divergence between island and continental species was also noted in both the PCAs and the Mahalanobis graph. Meanwhile, the statistical analysis of these species unfortunately provided no clues as to the ancestral state of their songs. However, a visual analysis of every species song, mapped on the dated phylogenetic tree, suggested that two distinct linages of simple and complex songs could be traced back approximately 10 million years. This allows for speculation as to the songs of now long extinct Cettiidae species as far back as the Miocene.

This study employed spectral analyses for acoustic measures of sustained vowel productions from a group of 20 adolescents and young adults with Friedreich's Ataxia (FA) and compared findings with a group of 20 age-equivalent and gender-matched normal control participants. State-of-the art spectral analyses from the Analysis of Dysphonia in Speech and Voice (ADSV) program, developed for various voice disorders from Kay Elemetrics, were applied to initial 2 second sustained vowel segments of the vowels /a/, /i/, and /o/. Spectral analyses included averages and standard deviations of Cepstral Peak Prominence (CPP), Cepstral Peak Prominence Standard Deviation (CPP SD), Low/High Spectral Ratio (L/H Ratio), Low/High Spectral Ratio Standard Deviation (L/H Ratio SD), Cepstral/Spectral Index of Dysphonia (CSID), and Mean Cepstral Peak Prominence Fundamental Frequency (Mean CPP F0). Statistical analyses revealed significant differences between the spectral analyses of voice characteristics of individuals with FA and those of normal controls for all measures except for CPP SD. The aim of these analyses was to determine spectral differences evident in vowel productions of individuals with FA using new cepstral-derived measures that characterize the phonatory instability and dis-coordination present in this disorder. Such research may not only help develop early non-invasive indicators of ataxia and track disease progression, but also serve to stimulate research into alleviating the symptoms of this devastating disease.

Cardiovascular disease is the leading cause of death globally and is responsible for taking 17.9 million lives per year. Despite the use of clinical treatments and detection methods, there remains a large population of individuals that suffer from CVD whose symptoms are left undetected and untreated prior to a life-threatening cardiac event. This highlights a need for an early detection method that can prevent the manifestation and worsening of the disease as well as address limitations of current early detection methods. An area of interest for early detection of CVD is subclinical atherosclerosis, which is the long, early, asymptomatic stage of plaque formation. Subclinical atherosclerosis has been namely associated with endothelial dysfunction and is the result of the pathological state of the endothelium due to its impact on vascular homeostasis, thrombosis, and vascular tone. Endothelial dysfunction is a result of several factors contributing to and promoting inflammation and results in changes in biological pathways that can alter the surface of the endothelium. This surface modification or added roughness changes the flow profile from laminar to turbulent flow due to the decreased shear stress on the vascular wall. Current detection methods such as carotid intima media thickness (CIMT) and flow-mediated dilation (FMD) targeted at identifying the early stages of atherosclerosis present limitations such as identifying late-stage effects of plaque formation and subjective readings highlight the need for a different approach to early detection. This experimental study aims to present a possible method of detecting the morphological changes of the endothelium due to inflammation through acoustic analysis of flow. Three silicone artery phantom groups were created with different degrees of inner diameter surface roughness to explore the relationship between relative roughness and sound associated with fluid flow. The results of this study are power spectral density graphs (PSD) which show frequency peaks associated with each of the phantoms at a theoretical laminar and turbulent Reynolds number. The PSD graphs show that there is a difference in frequency response between a smooth and rough artery phantom at the same flow rate providing preliminary support that sound analysis of fluid flow could provide information regarding early-stage cardiovascular disease.

The digital transformation of engineering design processes is essential for the aerospace industry to remain competitive in the global market. Multidisciplinary design optimization (MDO) frameworks play a crucial role in this transformation by integrating various engineering disciplines and enabling the optimization of complex spacecraft structures. Since the design team consists of multiple entities from different domains working together to build the final product, the design and analysis tools must be readily available and compatible. An integrated approach is required to handle the problem's complexity efficiently. Additionally, most aerospace structures are made from composite panels. It is challenging to optimize such panels as they require the satisfaction of constraints where the design ply thicknesses and orientations can only take discrete values prescribed by the manufacturers. Heuristics such as particle swarm or genetic algorithms are inefficient because they provide sub-optimal solutions when the number of design variables is large. They also are computationally expensive in handling the combinatorial nature of the problem. To overcome these challenges, this work proposes a two-fold solution that integrates multiple disciplines and efficiently optimizes composite spacecraft structures by building a rapid design framework. The proposed model-based design framework for spacecraft structures integrates commercially available software from Siemens packages such as NX and HEEDS and open-source Python libraries. The framework can handle multiple objectives, constraint non-linearities, and discrete design variables efficiently using a combination of black-box global optimization algorithms and Mixed Integer Programming (MIP)-based optimization techniques developed in this work. Lamination parameters and MIP are adopted to optimize composite panels efficiently. The framework integrates structural, thermal and acoustic analysis to optimize the spacecraft's overall performance while satisfying multiple design constraints. Its capabilities are demonstrated in optimizing a small spacecraft structure for required structural performance under various static and dynamic loading conditions when the spacecraft is inside the launch vehicle or operating in orbit. / Doctor of Philosophy / The design of new spacecraft takes several years and requires significant resources. The primary design objective is to minimize spacecraft mass/cost while satisfying the mission requirements. This is done by altering the structure's geometric and material properties. Most spacecraft panels are made from composite materials where the orientations of fiber paths and the thickness of the panel determine its strength and stiffness. Finding the best values for these parameters cannot be done efficiently using existing optimization algorithms, as several combinations of orientations can give a similar performance which can be subpar. In this dissertation, mathematical programming is adopted for fast evaluation of optimum panel properties, thereby saving a significant amount of resources compared to conventional techniques. Moreover, the requirements that govern the design process are handled one at a time in an organization. This leads to discrepancies in the various teams' designs that satisfy all requirements. A framework is built to integrate all requirements to account for their conflicting nature and quickly give the best possible spacecraft structural design configuration.

Background: Technological advancements in speech acoustic analysis have led to the development of spectral/cepstral analyses due to questions regarding the validity of traditional time-based measures (i.e., Jitter, Shimmer, and Harmonics-to-Noise-Ratio) in objectifying perturbations in dysphonic voices. Aim: This study investigated the validity of time-based measures in discriminating those with Friedreich’s ataxia (FA) from normal voiced (NV) peers when compared to cepstral-spectral measures. Method: A total of 120 sustained vowel phonations from an existing database of 40 participants (20 FA; 20 NV) of the vowels /ɑ/, /i/, and /o/ were analyzed to determine which set of variables (i.e., time-based vs. cepstral-spectral) better predicted group membership. Four variables of time-based measures (Jitter Local %, Jitter RAP, Shimmer Local %, Shimmer APQ11, and HNR) were analyzed via the freeware program PRAAT and compared to four cepstral-spectral measures (Cepstral Peak Prominence, Cepstral Peak Prominence Standard Deviation, Low/High Ratio Standard Deviation, and the Cepstral/ Spectral Index of Dysphonia) extracted from the Analysis of Dysphonia in Speech and Voice (ADSV) software program. Results: Findings from a discriminant analysis showed sensitivity and specificity results to be better for ADSV measures; 100% of those in the FA group were classified correctly (sensitivity), and 95% of members in the NV group were correctly identified (specificity) as compared to PRAAT (70% sensitivity and 85% specificity). Conclusions: Cepstral-spectral measures are much more accurate in discriminating between those with FA and NV peers as compared to time-based estimates.

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