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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

Aspectos acústicos da domesticação: os chamados de alerta e de corte do preá Cavia aperea e da cobaia Cavia porcellus. / Acoustic aspects of domestication: vocal signals of alarm and courtship in wild and domestic cavies.

Patrícia Ferreira Monticelli 28 July 2000 (has links)
A comparação entre cobaias (Cavia porcellus) e preás (Cavia aperea) fornece dados relevantes para se entender o processo de domesticação (Künzl e Sachser, 1999). No presente trabalho, foram registradas e analisadas sonograficamente (1) a vocalização de alerta, drr, em cobaias e em duas amostras de preás, uma observada em Münster (Alemanha), constituída de animais provenientes da Argentina, e outra constituída de animais provenientes de Itu (São Paulo) e (2) a vocalização de corte, purr, em cobaias e preás de Münster. Encontrou-se diferenças significativas entre C. porcellus e ambas as populações de C. aperea nos parâmetros temporais do drr (duração dos pulsos e dos intervalos entre eles e taxa de emissão) assim como diferenças significativas entre as populações de preás de Münster e de Itu (freqüências mínima e máxima da fundamental e freqüência máxima do chamado). No caso do purr, também houve diferenças significativas nos parâmetros temporais das espécies. Estes resultados demonstram a influência da domesticação e de fatores ecotípicos sobre a comunicação vocal e podem, juntamente com a análise sonográfica dos chamados de outras espécies do gênero Cavia, servir para resolução de questões filogenéticas deste grupo. Estudos com playbacks cruzados poderão eventualmente mostrar em que medida as diferenças de vocalização afetam o comportamento social e reprodutivo dos animais. / Comparision of guinea pigs (Cavia porcellus) and wild cavies (C. aperea) provides privileged models for the understanding of the behavioral effects of domestication (Künzl & Sachser, 1999). We here present a comparision between alarm (drr) and courtship (purr) vocalizations in domestic and wild types of cavies. We recorded and analyzed sonographically such calls in guinea pigs from our laboratory stock and in two samples of wild cavies, one from Münster University (Germany), bred from individuals captured in Argentina, and one from Itu (State of São Paulo). There were significant differences between domestic and both wild cavies samples in the temporal features of the drr (pulse duration, interpulse interval duration and rate of emission) and between the Münster and Itu samples in frequency related features (minimum and maximum freqüencies of the fundamental and maximum frequency of the call). Courtship calls purr of domestic and wild cavies from Münster also differed in temporal acoustical features. Our results show that both domestication and ecotypic factors may influence vocal communication. Playback studies could eventually show to what extent there is interspecific discrimination of the acoustic features of the alarm and courtship calls of cavies.
102

A deep dive into the Prinia atrogularis complex : A tale of birds and taxonomy

Groot, Damon January 2021 (has links)
The taxonomy of the taxa in the Prinia atrogularis-khasiana-superciliaris complex has changed several times in recent history. To this day, different world bird lists classify this complex as 1–3 species. These classifications are based mainly on morphological comparisons of museum specimens. No study has analysed the songs and genetics of this complex. This thesis focuses on the integrative taxonomy of this complex by analysing and comparing their song and mitochondrial cytochrome b (cytb) gene. Seventeen different variables from in total 172 individual songs were measured and analysed. A linear discriminant analysis showed a clear separation in song between atrogularis, khasiana and the superciliaris group (latter including the taxa superciliaris, erythropleura, klossi, dysancrita and waterstradti). The mitochondrial cytb phylogenetic tree produced using Bayesian inference suggested that atrogularis and khasiana split from superciliaris around 4.9 million years ago (mya), with atrogularis and khasiana splitting from each other around 3.4 mya. Based on the combined results of the song and cytb analysis I propose to recognise three species: Black-throated Prinia Prinia atrogularis, Rufous-crowned Prinia P. khasiana and Hill Prinia P. superciliaris. The study also showed some support for classifying klossi as a separate species, but acquisition of additional information is needed to verify this.
103

Speech development in toddlers at high and low risk for autism

Chenausky, Karen Virginia 27 October 2015 (has links)
Speech development in autism spectrum disorder (ASD) has rarely been studied, yet residual speech sound errors are over 30 times more common in children with ASD than in the general population. Two main theories could explain this. The Social Feedback Loop proposes that toddlers with ASD vocalize less often and so have fewer opportunities to benefit from adult feedback. Thus, fewer vocalizations and perceptible differences in those vocalizations should be found in toddlers with ASD. The Speech Attunement Framework proposes that while toddlers with ASD “tune in” to their native languages well enough to acquire language normally, they lack the ability to “tune up” their articulation to the same level of precision as typically-developing children. Thus, differences in the vocalizations of toddlers with ASD may be perceptible or not, and should exist irrespective of differences in vocalization rate. This study longitudinally examines vocalization rate, consonant inventory size, and voice-onset time (VOT) in syllable-initial bilabial stops using 30-minute speech samples from toddlers in three groups: those at low risk for ASD (LRC), those at high risk for ASD with ASD themselves (HRA+), and those at high risk for ASD without ASD (HRA ) . Transient delays in consonant development were found in both HRA- and HRA+, but only HRA+ toddlers vocalized less often. Further, the relationship between vocalization rate and consonant inventory was significantly different from LRC only for HRA-. VOT development was similar across groups, except that fewer HRA+ 36-month-olds produced distinct /b/ and /p/ populations, as measured by t-test and by Cohen’s d ≥ 0.8 between mean VOTs in the two populations of stops. Results support the Speech Attunement Framework. Consonant acquisition delays are not related to differences in vocalization rate and are not found only in toddlers who develop ASD. The finding of sub-perceptual acoustic differences in stop production in toddlers who develop ASD, with no accompanying differences in production rate, also supports the Speech Attunement Framework. This suggests that the Social Feedback Loop is not diminished in ASD by lower vocalization rate, but that toddlers with ASD may have diminished ability to monitor their own speech.
104

Automatic Recognition of Non-Verbal Acoustic Communication Events With Neural Networks

Anders, Franz 10 May 2022 (has links)
Non-verbal acoustic communication is of high importance to humans and animals: Infants use the voice as a primary communication tool. Animals of all kinds employ acoustic communication, such as chimpanzees, which use pant-hoot vocalizations for long-distance communication. Many applications require the assessment of such communication for a variety of analysis goals. Computational systems can support these areas through automatization of the assessment process. This is of particular importance in monitoring scenarios over large spatial and time scales, which are infeasible to perform manually. Algorithms for sound recognition have traditionally been based on conventional machine learning approaches. In recent years, so-called representation learning approaches have gained increasing popularity. This particularly includes deep learning approaches that feed raw data to deep neural networks. However, there remain open challenges in applying these approaches to automatic recognition of non-verbal acoustic communication events, such as compensating for small data set sizes. The leading question of this thesis is: How can we apply deep learning more effectively to automatic recognition of non-verbal acoustic communication events? The target communication types were specifically (1) infant vocalizations and (2) chimpanzee long-distance calls. This thesis comprises four studies that investigated aspects of this question: Study (A) investigated the assessment of infant vocalizations by laypersons. The central goal was to derive an infant vocalization classification scheme based on the laypersons' perception. The study method was based on the Nijmegen Protocol, where participants rated vocalization recordings through various items, such as affective ratings and class labels. Results showed a strong association between valence ratings and class labels, which was used to derive a classification scheme. Study (B) was a comparative study on various neural network types for the automatic classification of infant vocalizations. The goal was to determine the best performing network type among the currently most prevailing ones, while considering the influence of their architectural configuration. Results showed that convolutional neural networks outperformed recurrent neural networks and that the choice of the frequency and time aggregation layer inside the network is the most important architectural choice. Study (C) was a detailed investigation on computer vision-like convolutional neural networks for infant vocalization classification. The goal was to determine the most important architectural properties for increasing classification performance. Results confirmed the importance of the aggregation layer and additionally identified the input size of the fully-connected layers and the accumulated receptive field to be of major importance. Study (D) was an investigation on compensating class imbalance for chimpanzee call detection in naturalistic long-term recordings. The goal was to determine which compensation method among a selected group improved performance the most for a deep learning system. Results showed that spectrogram denoising was most effective, while methods for compensating relative imbalance either retained or decreased performance.:1. Introduction 2. Foundations in Automatic Recognition of Acoustic Communication 3. State of Research 4. Study (A): Investigation of the Assessment of Infant Vocalizations by Laypersons 5. Study (B): Comparison of Neural Network Types for Automatic Classification of Infant Vocalizations 6. Study (C): Detailed Investigation of CNNs for Automatic Classification of Infant Vocalizations 7. Study (D): Compensating Class Imbalance for Acoustic Chimpanzee Detection With Convolutional Recurrent Neural Networks 8. Conclusion and Collected Discussion 9. Appendix / Nonverbale akustische Kommunikation ist für Menschen und Tiere von großer Bedeutung: Säuglinge nutzen die Stimme als primäres Kommunikationsmittel. Schimpanse verwenden sogenannte 'Pant-hoots' und Trommeln zur Kommunikation über weite Entfernungen. Viele Anwendungen erfordern die Beurteilung solcher Kommunikation für verschiedenste Analyseziele. Algorithmen können solche Bereiche durch die Automatisierung der Beurteilung unterstützen. Dies ist besonders wichtig beim Monitoring langer Zeitspannen oder großer Gebiete, welche manuell nicht durchführbar sind. Algorithmen zur Geräuscherkennung verwendeten bisher größtenteils konventionelle Ansätzen des maschinellen Lernens. In den letzten Jahren hat eine alternative Herangehensweise Popularität gewonnen, das sogenannte Representation Learning. Dazu gehört insbesondere Deep Learning, bei dem Rohdaten in tiefe neuronale Netze eingespeist werden. Jedoch gibt es bei der Anwendung dieser Ansätze auf die automatische Erkennung von nonverbaler akustischer Kommunikation ungelöste Herausforderungen, wie z.B. die Kompensation der relativ kleinen Datenmengen. Die Leitfrage dieser Arbeit ist: Wie können wir Deep Learning effektiver zur automatischen Erkennung nonverbaler akustischer Kommunikation verwenden? Diese Arbeit konzentriert sich speziell auf zwei Kommunikationsarten: (1) vokale Laute von Säuglingen (2) Langstreckenrufe von Schimpansen. Diese Arbeit umfasst vier Studien, welche Aspekte dieser Frage untersuchen: Studie (A) untersuchte die Beurteilung von Säuglingslauten durch Laien. Zentrales Ziel war die Ableitung eines Klassifikationsschemas für Säuglingslaute auf der Grundlage der Wahrnehmung von Laien. Die Untersuchungsmethode basierte auf dem sogenannten Nijmegen-Protokoll. Hier beurteilten die Teilnehmenden Lautaufnahmen von Säuglingen anhand verschiedener Variablen, wie z.B. affektive Bewertungen und Klassenbezeichnungen. Die Ergebnisse zeigten eine starke Assoziation zwischen Valenzbewertungen und Klassenbezeichnungen, die zur Ableitung eines Klassifikationsschemas verwendet wurde. Studie (B) war eine vergleichende Studie verschiedener Typen neuronaler Netzwerke für die automatische Klassifizierung von Säuglingslauten. Ziel war es, den leistungsfähigsten Netzwerktyp unter den momentan verbreitetsten Typen zu ermitteln. Hierbei wurde der Einfluss verschiedener architektonischer Konfigurationen innerhalb der Typen berücksichtigt. Die Ergebnisse zeigten, dass Convolutional Neural Networks eine höhere Performance als Recurrent Neural Networks erreichten. Außerdem wurde gezeigt, dass die Wahl der Frequenz- und Zeitaggregationsschicht die wichtigste architektonische Entscheidung ist. Studie (C) war eine detaillierte Untersuchung von Computer Vision-ähnlichen Convolutional Neural Networks für die Klassifizierung von Säuglingslauten. Ziel war es, die wichtigsten architektonischen Eigenschaften zur Steigerung der Erkennungsperformance zu bestimmen. Die Ergebnisse bestätigten die Bedeutung der Aggregationsschicht. Zusätzlich Eigenschaften, die als wichtig identifiziert wurden, waren die Eingangsgröße der vollständig verbundenen Schichten und das akkumulierte rezeptive Feld. Studie (D) war eine Untersuchung zur Kompensation der Klassenimbalance zur Erkennung von Schimpansenrufen in Langzeitaufnahmen. Ziel war es, herauszufinden, welche Kompensationsmethode aus einer Menge ausgewählter Methoden die Performance eines Deep Learning Systems am meisten verbessert. Die Ergebnisse zeigten, dass Spektrogrammentrauschen am effektivsten war, während Methoden zur Kompensation des relativen Ungleichgewichts die Performance entweder gleichhielten oder verringerten.:1. Introduction 2. Foundations in Automatic Recognition of Acoustic Communication 3. State of Research 4. Study (A): Investigation of the Assessment of Infant Vocalizations by Laypersons 5. Study (B): Comparison of Neural Network Types for Automatic Classification of Infant Vocalizations 6. Study (C): Detailed Investigation of CNNs for Automatic Classification of Infant Vocalizations 7. Study (D): Compensating Class Imbalance for Acoustic Chimpanzee Detection With Convolutional Recurrent Neural Networks 8. Conclusion and Collected Discussion 9. Appendix
105

Call Categorization and Vocal Behavior of the Florida Manatee (Trichechus manatus latirostris)

Unknown Date (has links)
Florida manatees are semisocial marine mammals that vocalize when interacting with conspecifics and to maintain contact with offspring. While many aspects of their biology have been studied, there is a dearth of information on the diversity and complexity of vocal behavior during social, nonsocial, and stressful situations. Investigations of vocal communication repertoires which define, categorize, and correlate varied call types with behavior are needed in order to understand the behavioral and social function of associated calls. Arguably the most important social bond in manatees is the period of cow/calf dependency and empirical evidence indicates cows recognize the vocalizations of offspring. Exploration of individually distinctive vocal features can provide insight on which parameters might be salient to facilitate recognition between cows/calves. This study is focused on vocal communication in Florida manatees, how calls are structured, utilized and function while animals are distressed and during social interactions in their shallow water habitats. Hydrophones recorded vocalizations from individual calves and manatees in different behavioral contexts and varying size aggregations. Analysis of the vocal repertoire indicated manatee vocalizations can be parsed into five broadly defined call types which include the hill-shaped high squeak, tonal squeak, noisy squeal, two toned chirp, and the combinatorial squeak-squeal. Furthermore, the high squeak is likely a discrete call whereas the others are graded and do not have strict boundaries between call types (Chapter 2). Broadly defined call types were used to explore call usage with variations in behavior, group size, and group composition (Chapter 3). Manatees vocalized using few call types and altered structural parameters depending on behavioral state. Calls were longer and more frequency modulated when stressed. Vocalizations produced while cavorting were higher in entropy and more frequency modulated than when manatees were resting or feeding. Vocalizations obtained from individual calves suggest that the high squeak is a stereotypical call that is produced by smaller calves. All calves had individually distinctive acoustic features that could potentially be used in recognition (Chapter 4). Lower fundamental frequencies and higher emphasized frequencies from smaller calves suggest that the fundamental frequency may not be a reliable indicator of body size in calves. This research increases our knowledge of the vocal behavior and call characteristics of the Florida manatee. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection
106

The Effect of Time of Expsoure to Polychlorinated Biphenyl (PCB) on Thyroid Status and Ultrasonic Vocalizations in Sprague Dawley Rats

King, Samantha L. 29 July 2013 (has links)
No description available.
107

Information in a long-distance vocal signal: chorus howling in the coyote (canis latrans)

Hallberg, Karen Irene 19 September 2007 (has links)
No description available.
108

Early Social Communication Vulnerabilities of Children at Genetic Risk for Autism Spectrum Disorder

Lisa R. Hamrick (8941913) 26 July 2022 (has links)
<p>Early detection and characterization of autism spectrum disorder (ASD) may be improved by incorporating ecologically valid methods into ASD screening and assessment, capitalizing on prospective monitoring of high-risk populations, and targeting highly informative ASD features that emerge early in development. The present study aims to address these barriers by characterizing early vocal and pre-linguistic communication features present during naturalistic behavior samples of young children with neurogenetic syndromes (NGS). Participants were 39 children aged 5-30 months diagnosed with an NGS and 39 children aged 4-26 months at low risk for developmental delays. Participants completed a daylong audio recording of child vocalizations from which measures of early vocal features (child vocalization rate, canonical babbling ratio, and pitch variability) were obtained. Participants and their mothers also completed an unstructured play-based task during which pre-linguistic communicative features (communication complexity and function) were coded. We first used Bayesian analyses to compare the early vocal and pre-linguistic communication features of children with NGS to those of children at low risk for developmental delays. Children with NGS used less canonical babble, lower communication complexity overall and for behaviors for the purposes of joint attention. Next, we conducted a cluster analysis of early vocal and pre-linguistic communication features using the full sample of NGS and low-risk participants. The selected model identified 6 clusters that were primarily differentiated by canonical babbling and communicative function. These clusters differentiated participants beyond risk status, chronological age and adaptive age. Furthermore, certain clusters reflected differences in adaptive communication and socialization skills that may be relevant to early ASD profiles. These findings suggest that canonical babble and communicative function provide meaningful information about early developmental risk and may be useful to incorporate into the ASD screening and diagnostic processes.</p>
109

Pant-grunts in wild chimpanzees (Pan troglodytes schweinfurthii) : the vocal development of a social signal

Laporte, Marion N. C. January 2011 (has links)
While the gestural communication of apes is widely recognised as intentional and flexible, their vocal communication still remains considered as mostly genetically determined and emotionally bound. Trying to limit the direct projections of linguistic concepts, that are far from holding a unified view on what constitute human language, this thesis presents a detailed description of the pant-grunt vocalisation usage and development in the chimpanzees (Pan troglodytes schweinfurthii) of the Budongo forest, Uganda. Pant-grunts are one of the most social vocalisations of the chimpanzee vocal repertoire and are always given from a subordinate individual to a dominant. The question of how such a signal is used and develops is critical for our understanding of chimpanzee social and vocal complexity in an ontogenetical and phylogenetical perpective. Results suggest that pant-grunt vocalisations can be used in a flexible way, both in their form and usage within a social group. More specifically, chimpanzees seemed to take into account the number and identity of surrounding individuals before producing these vocalisations. At the acoustic level, pant-grunts seem to be very variable vocalisations that corresponded to different social situations commonly encountered. Grunts are one of the first vocalisations produced by babies but they are not first produced in social contexts. Although some modifications of the social grunts form and usage could not entirely be attributed to maturation only, the role of the mother seemed to be restricted. Her direct influence was perhaps more visible in the rhythmic patterns of chorusing events. Taken together, this thesis suggests that chimpanzee vocalisations are more flexible in their usage, production and acquisition than previously thought and might therefore be more similar to gestural communication.
110

De l'intimité à la complicité : la chanson-action comme organisateur de l'attention chez le bébé de trois à six mois. / From intimacy to complicity : how do action-songs organize attention in 3- to 6-months-old infants.

Delavenne, Anne 17 February 2011 (has links)
L’objectif de cette recherche est d’étudier la coordination temporelle entre l’organisation de la performance maternelle (chant et gestes des mains), les variations de l’attention visuelle et la vocalisation du bébé à 3 mois et à 6 mois au cours de la ‘chanson-action’ française ‘les marionnettes’. Le terme ‘chanson-action’ désigne des routines interactives associant une ‘mise en scène’ des mains (ici de la mère) coordonnée à un chant pour bébé. Le ‘chanter-bébé’ fait partie des premières stimulations musicales du bébé. Des recherches expérimentales ont mis en évidence qu’il possède plusieurs fonctions et qu’en particulier il maintient l’attention du bébé au cours des échanges. Les ‘chansons-actions’ apparaissent dans le cours des interactions précoces un peu avant le milieu de la première année du bébé. Or des expériences ont montré qu’à cet âge précoce le bébé semble déjà capable de partager son attention entre la mère et un autre centre d’intérêt dans certaines conditions, en particulier lorsque la mère manipule un objet familier. Les ‘chansons-actions’ apparaissent alors comme une situation naturelle permettant d’étudier l’aptitude du bébé à partager son attention. Nous avons donc cherché à tester l’hypothèse centrale selon laquelle l’organisation hiérarchisée de la performance maternelle et en particulier du chant devait fournir un cadre organisant les variations dynamiques de l’attention visuelle du bébé. Nous pensions de plus que l’organisation temporelle de ses vocalisations devait refléter sa sensibilité à cette organisation musicale et qu’il devait vocaliser à des moments saillants de la chanson-action. Nous avons choisi d’étudier les échanges de mêmes dyades à 3 mois et à 6 mois car ces âges sont périphériques à l’émergence spontanée des ‘chansons-actions’ dans le répertoire des routines interactives de la mère et du bébé. Nous voulions ainsi explorer l’évolution de la coordination entre l’organisation temporelle de la performance maternelle et les variations de l’attention du bébé.Nous avons étudié les échanges de 20 dyades à 3 mois (12 dyades ‘mère-garçon’ et 8 dyades ‘mère-fille’) et de 18 de ces mêmes dyades à 6 mois (10 dyades ‘mère-garçon’ et 8 dyades ‘mère-fille’). L’originalité de notre recherche est d’explorer l’évolution dynamique des variations de l’attention du bébé au cours de la chanson-action... / The aim of this study was to analyze the temporal coordination between the organization of the maternal performance (singing and hand gesturing), the visual attention and vocalization of the infant at 3- and 6-months during sequences of the French ‘action-song’ ‘les marionnettes’. The word ‘action-song’ is used to refer to interactive routines that combine hand gestures coordinated with a baby song. Infant-directed singing has been shown to be among the first musical stimulations addressed infants. Experimental studies have demonstrated that it possesses several functions and that one of them is maintaining the infant’s attention. Action-songs emerge in interactions at about 4-months. Experimental studies have proved that the infant exhibits the ability to share her attention between the mother and another object of interest, in particular when it is a familiar object that the mother holds in her hands. Actions-songs appear to be a natural situation that allows us to study this ability. We tested the central hypothesis that the hierarchical levels of maternal singing performance would provide a frame that would organize the dynamic variations of the infant’s visual attention. Moreover the infant would vocalize at specific moments of the musical structure of maternal singing. We studied the exchanges of the same dyads at 3- and 6-months to explore the developmental trajectory of the coordination between the temporal organization of the maternal performance and the infant’s visual attention.We studied the interactions of 20 dyads at 3 months (12 boys and 8 girls) and of 18 of those dyads at 6 months (10 boys and 8 girls). We performed both video and acoustic microanalyses to study the dynamic variations of infant’s attention during the action-song. Thus, each gaze orientation of the infant was associated with a specific element of the maternal singing. Our results showed that maternal singing was articulated at three hierarchical temporal levels (verse, line, pulse) both at 3- and at 6-months. At 3 months the infant’s attention was oriented mainly towards the mother’s face. The variations of the infant’s attention were coordinated with the phrasing of maternal singing and the infant reoriented her attention towards the hands just before the end of the verse. Infants’ vocalizations also occurred at the end of the verse. At 6-months, infants were more attentive to the mother’s hands. Six-month-olds reoriented her attention towards the mother’s face at the end of the verse. Infants’ vocalizations were synchronized with pulse of the maternal singing. Furthermore our results exhibited gender differences at 3- and at 6-months. The performance of mothers of boys was more regular than the performance of mothers of girls. We suggest that actions-songs provide a frame that scaffolds the ability of the infant to share her attention between the mother’s face and hands.

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