The thesis identifies some of the most salient acoustic and descriptive features employed in listeners' representations of sounds focussing on similarity judgements. A range of descriptive data (including word pair and imagery/word use) was collected alongside acoustic measures for the sound stimuli employed. The sounds employed were initially all abstract in nature but environmental sounds were included in later experiments. A painwise comparison task and a grouping task were employed to collect (dis)similarity data for multidimensional scaling and hierarchical cluster analyses. These provided visual output that represented the sounds' perceived similarities. Following participants' similarity judgements correlational techniques identified which of the acoustic and descriptive features helped to explain the dimensions identified by the MDS. Results across all nine experiments indicated that both acoustic and descriptive features contributed to listeners' similarity judgements and that the influence of these varied for the different sound sets employed. Familiarity with the sounds was identified as an additional feature that played a key role in the way participants used the available information in their grouping decisions. There was also a clear indication that the category to which a sounds source object belonged was making an important contribution to the similarity judgements for sounds rated as familiar. The work highlights a complex and variable relationship in the use of descriptive and acoustic features. Further the work has investigated the similarities and differences in participants' judgements depending on the data collection technique used i.e. pairwise comparison or grouping task. These findings have implications for the development of future models of auditory cognition. The thesis suggests that the perception of sound with particular reference to similarity is a complex interplay of features that goes far beyond understanding acoustic features alone.

This thesis investigates the relationship between colour perception and colour language. Three questions are addressed. The first relates to the influence of colour- category membership on colour perception, the second to potential influences of colour language on colour perception. The third question asks whether non-linguistic differences in colour perception may influence differences in colour language. Experimental studies provide evidence for categorical colour perception. However, unlike previous studies, the experiments reported here found no evidence that linguistic colour categories underpin, or influence, colour perception. The reasons for this difference are discussed. The findings support the view that linguistic colour categories reflect non-linguistic perceptual colour categories. Finally evidence is presented suggesting that physiological differences in colour perception may influence the colour categories encoded by languages.

The mapping of acoustic speech signals onto linguistic representations is highly complex, and a number of competing models of both system architecture and auditory processing mechanisms have been proposed. Detailed investigation of processing in both normal and aphasic listeners provides insights into the nature of the underlying processing mechanisms, and can be used to test the empirical validity of theoretical models. Three related experiments were designed to explore aspects of the complex interrelations between phonetic, lexical and semantic levels of representation in the auditory speech processing of five adults with chronic aphasia and ten controls. The first experiment explored whether the effects of word frequency and imageability that affect recognition of words heard in isolation exert the same influence when words are heard in the context of a meaningful sentence. The second experiment compared discrimination of voice, place and manner contrasts in nonword and word minimal pairs, to explore the effect of the lexical status of the carrier syllable on phonological encoding. The third experiment used a picture-word verification task to explore the effects of semantic contexts provided by pictures on discrimination. Stimuli were closely matched across experiments two and three to allow detailed comparison of lexical and semantic influences on processing. Accuracy and reaction time data were collected, with control group data indicating normal patterns of performance. Aphasic data were analysed mainly as a series of single cases, and interpreted in the light of each individual's performance on a range of language processing assessments. The results revealed a number of different patterns in the effects of linguistic context for control and aphasic listeners, with aphasic listeners showing greater influences of lexical and semantic contexts on processing. The results of all three experiments are discussed in relation to competing theoretical models of auditory processing. It is argued that a distributed connectionist model currently accounts for the data more effectively than either localist connectionist or cognitive neuropsychological models.

It has been suggested that much of the information we acquire from our external environment involves processes that do not require conscious awareness (e.g. Reber, 1989; Reber and Winter, 1994). Such knowledge acquisition has been termed implicit learning and this has been put forward as a fundamental process in allowing learning of complex information (e.g. Reber, 1992; Schmidke and Heuer, 1997). It has been proposed that acquisition of the underlying rule structure of stimulus events provides an indication of such a process as being fundamental and general. In contrast, learning bound to more peripheral processes should only be shown when subjects learn, for example, surface features of stimuli or a sequence of motor responses, but not the underlying rules (e.g. Perruchet and Pacteau, 1990; Seger, 1998). The research in this thesis investigates systematically whether implicit learning of sound stimuli behaves any differently to such learning of visual stimuli. This expands the empirical scope of previous studies in the implicit learning field and allows assessment of such processes as fundamental and general. Chapter 1 provides a background to implicit learning in general and introduces the different concepts involved. Chapters 2 to 4 investigated the generality of findings from visual implicit learning studies in the auditory domain. In particular, they studied the role of rule abstraction in sequence learning (Nissen and Bullemer, 1987) and invariant learning tasks (McGeorge and Burton, 1990). Findings from the sequence learning experiments in Chapters 2 and 3 suggest that subjects were unable to abstract the underlying rule structure of stimuli, as would have been evident from learning of the auditory sequences employed by listening alone. Instead, subjects were only able to learn the relevant associations between their actions (keypress responses) and a set of stimuli. These findings add to evidence from visual implicit learning studies that found peripheral processes involved in such learning. Findings from the invariant learning experiments in Chapter 4 show what types of auditory invariant features subjects can and cannot learn. This identified for the first time the exact information, or rule, that subjects acquire in such a task in an auditory context. Additionally, it provides some evidence that explicit processes may have been involved. Overall, the findings from the experiments in this thesis put into question that implicit learning is a fundamental process, which involves implicit rule abstraction.

Practice improves performance on many basic auditory tasks. However, while the phenomenon of auditory perceptual learning is well established, little is known about the mechanisms underlying such improvements. What is learned during auditory perceptual learning? This thesis attempts to answer this question by applying models of performance to behavioural response data, and examining which parameters change with practice. On a simple pure tone discrimination task, learning is shown to primarily represent a reduction in internal noise, with encoding efficiency, attentiveness and bias appearing invariant. In a more complex auditory detection task, learning and development are also shown to involve improvements in listening strategy, with listeners becoming better able to selectively-attend to task-relevant information. Finally, task performance is potentially constrained not just by the strength of the sensory evidence, but also by the efficiency of the wider decision process that the sensory evidence informs. Thus, in the final chapters learning is also shown to involve reductions in both stationary and nonstationary bias. In short, learning is shown to be subserved by multiple mechanisms that: operate in parallel, vary in importance depending on the task demands, and incorporate both sensory and non-sensory processes. The methods of analysis described herein are shown to effectively partition components of perception in normal hearing children and adults, and may help to understand learning processes needed for the rehabilitation of listening difficulties.

The auditory attention skills of alterting, orienting, and executive control were assessed using behavioural and neuroimaging techniques. Initially, an auditory analgue of the visual attention network test (ANT) (FAN, McCandliss, Sommer, Raz, & Posner, 2002) was created and tested alongside the visual ANT in a group of 40 healthy subjects. The results from this study showed similarities between auditory and visual spatial orienting. An fMRI study was conducted to investigate whether the similar behavioural measures of auditory and visual executive control were the result of common cortical mechanisms. The results were consistent with a supramodal anterior network involved in conflict monitoring and resolution. Auditory orienting of attention was investigated through a series of behavioural experiments. The first investigated listeners' ability to benefit from cues to location, to pitch, and to both location and pitch, in a vowel-identification task. Subjects were able to benefit from all three types of cues but did not gain additive benefit from being cued to both location and pitch, suggesting that attention was being directed to an auditory object comprising both features. The following seven experiments investigated auditory spatial orienting in non-spatial tasks. These experiments revealed a robust exogenous (automatic) auditory orienting effect, which was relatively insensitive to task differences. However, endogenous (voluntary) auditory orienting effects were small and highly variable across subjects. It is hypothesised that differences between auditory and visual spatial orienting reflect the relative importance of spatial information in the two modalities, and differences in the neural coding of auditory and visual spatial information.

Cette thèse vise à caractériser le traitement auditif des informations spectro-temporelles impliquées dans la perception de la parole au cours du développement précoce. Dans ce but, les capacités de discrimination de contrastes phonétiques sont évaluées à l’aide de deux méthodes comportementales chez des enfants âgés de 6 et 10 mois. Les sons de parole sont dégradés par des « vocodeurs » conçus pour réduire sélectivement les modulations spectrales et/ou temporelles des stimuli phonétiquement contrastés.Les trois premières études de cette thèse montrent que les informations spectro-temporelles fines de la parole (les indices de modulation de fréquence et détails spectraux) ne sont pas nécessaires aux enfants français de 6 mois pour percevoir le trait phonétique de voisement et de lieu d’articulation. Comme pour les adultes français, les informations de modulation d’amplitude les plus lentes semblent suffire pour percevoir ces traits phonétiques. Les deux dernières études montrent cependant que les informations spectro-temporelles fines sont requises pour la discrimination de tons lexicaux (variations de hauteur liée au sens de mots monosyllabiques) chez les enfants français et taiwanais de 6 mois. De plus, ces études montrent l’influence de l’expérience linguistique sur le poids perceptif de ces informations de modulations dans la discrimination de la parole chez les jeunes adultes et les enfants français et taiwanais de 10 mois.Ces études montrent que les mécanismes auditifs spectro-temporels sous-tendant la perception de la parole sont efficaces dès l’âge de 6 mois, mais que ceux-ci vont être influencés par l’exposition à l’environnement linguistique dans les mois suivants. Enfin, cette thèse discute les implications de ces résultats vis-à-vis de l’implantation précoce des enfants sourds profonds qui reçoivent des informations de modulations dégradées. / The goal of this doctoral research was to characterize the auditory processing of the spectro-temporal cues involved in speech perception during development. The ability to discriminate phonetic contrasts was evaluated in 6- and 10-month-old infants using two behavioral methods. The speech sounds were processed by “vocoders” designed to reduce selectively the spectro-temporal modulation content of the phonetically contrasting stimuli. The first three studies showed that fine spectro-temporal modulation cues (the frequency-modulation cues and spectral details) are not required for the discrimination of voicing and place of articulation in French-learning 6-month-old infants. As for French adults, 6-month-old infants can discriminate those phonetic features on the sole basis of the slowest amplitude-modulation cues. The last two studies revealed that the fine modulation cues are required for lexical-tone (pitch variations related to the meaning of one-syllable word) discrimination in French- and Mandarin-learning 6-month-old infants. Furthermore, the results showed the influence of linguistic experience on the perceptual weight of these modulation cues in both young adults and 10-month-old infants learning either French or Mandarin.This doctoral research showed that the spectro-temporal auditory mechanisms involved in speech perception are efficient at 6 months of age, but will be influenced by the linguistic environment during the following months. Finally, the present research discusses the implications of these findings for cochlear implantation in profoundly deaf infants who have only access to impoverished speech modulation cues.

L'objectif général de cette thèse est d'explorer comment les enfantes perçoivent des traits de surface du langage à différents niveaux. Plus spécifiquement, on a examiné dans une population typique et atypique 1) la perception des traits acoustiques de bas-niveau et sa relation avec le développement du vocabulaire, et 2) la sensibilité à la fréquence des mots pour générer la représentation linguistique abstraite des catégories lexicales et de leur ordre relatif. Selon les modèles de bootstrapping, il est possible d'extraire des informations structurelles et abstraites de la langue à partir de traits acoustiques disponibles dans l'input et corrélés avec la structure linguistique sous-jacente (p. ex. grammaire et syntaxe). Pour examiner le lien entre la perception de bas niveau, les traits de surfaces et les connaissances grammaticales plus abstraites, cette thèse s'articule en deux parties principales. Dans la première partie, deux études longitudinales sont présentées. Chaque enfant était testé sur son seuil de discrimination auditive (avec un paradigme de traitement rapide) et sur une tâche de reconnaissance visuelle pour contrôler les compétences cognitives. Le seuil acoustique était évalué en utilisant des sons non-linguistiques (tons) dans un groupe d'enfants et linguistiques (syllabes) dans un autre groupe d'enfants à 9 mois pour déterminer si l'impact du traitement auditif est spécifique au langage. Enfin, le niveau de vocabulaire a été mesuré à 12, 14, 18 et 24 mois et un test cognitif (Mullen Scale) a été réalisé entre 18 et 20 mois comme supplémentaire contrôle cognitif. Les résultats montrent que les capacités mesurées sont prédictives du développement du vocabulaire chez les enfantes typiques. De plus, les enfants atypiques ont montré des capacités de traitement moins efficaces dans les modalités visuelle et acoustique. Dans la deuxième partie, le rôle de la fréquence des mots dans l'amorçage des catégories lexicales des mots de fonction et de contenu et leur ordre relatif est explorée. Les deux catégories lexicales sont différentes dans leur fonction linguistique, leurs caractéristiques phonologiques et leur fréquence dans la parole. Ainsi, leur catégorisation basée sur la fréquence pourrait constituer un mécanisme initial robuste pour acquérir les constructions de base de la langue. Comme les mots de fonction constituent une classe fermée, alors que les mots de contenu constituent de classes ouvertes, nous avons examiné si les nourrissons français âgés de 8 mois étaient sensibles à la fréquence des mots pour catégoriser les mots de fonction et pour les traiter comme des éléments non-remplaçables dans des classes fermées, et les mots de contenu comme des éléments librement remplaçables dans des classes ouvertes. Les cinq expériences de grammaire artificielle menées ont confirmé cette hypothèse. De plus, les nourrissons associent l'ordre relatif de ces catégories avec l'ordre des mots de base de leur langue maternelle, le français. Les participants atypiques ont montré des capacités de discrimination, de codage et de mémoire inférieures à leurs pairs typiques. En conclusion, ce travail a permis une meilleure compréhension des capacités de perception contribuant au développement du langage. De plus, cette thèse a identifié de potentiels marqueurs comportementaux pouvant servir à l'identification précoce des apprenants atypiques. / The purpose of this work is to explore how infants perceive surface features of language at different levels of processing. Specifically, in both typical and atypical populations, we examined 1) the processing of low-level auditory cues and its relationship with later language outcomes and 2) the sensitivity to word frequency to create abstract linguistic representations of lexical categories and their relative word order. Accordingly to bootstrapping models learners are able to extract abstract, structural and hence directly unobservable properties of the target language from perceptually available surface cues in the input that correlate with the underlying structure. Indeed, infants are sensitive to certain acoustic and phonological properties of the speech input, which in turn correlate with specific grammatical/syntactic structures. In order to map the link between the perception of these low-level, surface cues and more abstract grammatical knowledge, this work is organized in two main parts. In the first part, two longitudinal studies are reported. Each infant received an auditory discrimination threshold task (using the rapid auditory processing paradigm) followed by a habituation/visual novelty detection task used as a control for general cognitive skills. The auditory discrimination threshold was evaluated using non-linguistic (tones) sounds in one cohort of infants and linguistic sounds (syllables) in another cohort of infants at 9 months in order to investigate the language-specificity of the process within the auditory modality. Subsequently, infants' vocabulary was assessed at 12-14-18 and 24 months and a cognitive test (Mullen scale) was performed at 18-20 months as another control measure for early processing competence. Results show that early processing abilities are predictive of later vocabulary size in typical infants. Importantly, atypical participants exhibited slower and less efficient processing abilities in both visual and acoustic modality. In the second part, the role of word frequency in bootstrapping the basic lexical categories of function and content words and their relative order is explored. The two lexical categories differ in their linguistic functions, phonological makeup and frequency of occurrence. Thus, their frequency-based discrimination could constitute a powerful initial mechanism for infants to acquire the basic building blocks of language. As functors constitute closed classes, while content words come in open classes, we examined whether 8 month-old French monolinguals relied on word frequency to categorize and track functors as non-replaceable items in a closed class, and content words as freely replaceable items in open classes. In five artificial grammar-learning experiments we have found that infants treat frequent words as belonging to closed classes, and infrequent words as belonging to open classes and they map the relative order of these categories onto the basic word order of their native language, French, a functor-initial language. Importantly, atypical participants showed lower ability of discrimination, encoding and memory when compared to typically developing peers. Overall this work contributes to a better understanding of the perceptual abilities that directly contribute to language development. Moreover, it proposes possible behavioural markers that can be potentially useful in the early identification of atypical learners.

Cette recherche visait à clarifier les mécanismes de bas niveau impliqués dans la détection de la modulation de fréquence (FM). Les sons naturels véhiculent des modulations d’amplitude et de fréquence saillantes essentielles à la communication. L’analyse des réponses de neurones auditifs du noyau cochléaire montre que les propriétés spectro-temporelles des stimuli de FM de basse cadence sont représentées par deux mécanismes distincts basés sur le verrouillage en phase à l’enveloppe temporelle (ENV) et à la structure temporelle fine (TFS). La contribution relative de chaque mécanisme s’avère très dépendante des paramètres de stimulation (fréquence porteuse, cadence de modulation et profondeur de modulation) mais aussi du type de neurones, chacun étant spécialisé pour un type de représentation ou l'autre. L’existence de ces deux mécanismes de codage neuronal a été confirmée chez les auditeurs humains en utilisant deux paradigmes psychophysiques. Les résultats de ces études démontrent également que le mécanisme de codage de TFS est efficace dans des conditions d'écoute défavorables (e.g. en présence de modulations interférentes). Cependant, le mécanisme de codage de TFS est susceptible de se dégrader avec l'âge et plus encore avec la perte auditive, alors que le mécanisme de codage d’ENV semble relativement épargné. Deux modèles computationnels ont été développés afin d’expliquer les contributions des indices d’ENV et de TFS dans le système auditif normal et malentendant. / This research aimed at clarifying the low-level mechanisms involved in frequency-modulation (FM) detection. Natural sounds convey salient amplitude- and frequency-modulation patterns crucial for communication. Results from single auditory neurons in the cochlear nucleus show that the spectro-temporal properties of low-rate FM stimuli are accurately represented by two distinct mechanisms based on neural phase-locking to temporal envelope (ENV) and temporal fine structure (TFS) cues. The relative contribution of each mechanism was found to be highly dependent on stimulus parameters (carrier frequency, modulation rate and modulation depth) and also on the type of neuron, with clear specializations for one type of representation or the other. The validity of those two neural encoding mechanisms was confirmed for human listeners using two psychophysical paradigms. Results from those studies also demonstrate that the TFS coding mechanism is efficient in adverse listening conditions, like in the presence of interfering modulations. However, the TFS coding mechanism is prone to decline with age and even more with hearing loss, while the ENV coding mechanism seems relatively spared. Two computational models were developed to fully explain the contributions of ENV and TFS cues in the normal and impaired auditory system.

L'étude de ce que l'on nomme « rhétorique musicale » nous semble pouvoir offrir un éclairage spécifique sur la question de la musique et des émotions. En effet, les deux champs de réflexion en philosophie de la musique dont il est question font l'objet d'un intérêt qui se manifeste au cours de ces dernières années. Aussi, nous considérons que la rhétorique musicale et le phénomène particulier de la poétique musicale germanique sont de nature à structurer une telle étude, tant par les choix qu'ils présupposent (comme le fait que les émotions y sont un moyen destiné à produire un effet) que par ceux qu'ils délaissent. Notre recherche suivra les trois principales étapes suivantes : (a) une étude des aspects de la question antérieurs à la musica poetica (dans la Grèce antique, dans la liturgie luthérienne, dans la théorie musicale italienne) ; (b) un examen détaillé du thème des passions dans les traités de l’Allemagne baroque ; (c) un parcours concernant l’évolution de la question jusqu’aux débats actuels. / Studying “musical rhetoric” seems likely to bring some specific light about the topic of music and emotions. Both fields of research in philosophy of music involved arouse an interest, especially last years. Therefore, we regard musical rhetoric and the distinctive phenomenon of German musical poetics as able to structure such a studying, through choices they suppose (for example, the fact that emotions are means for have an effect) and choices they leave. Our investigation includes the three main following parts: (a) some study about facets of the subject prior to musica poetica (in Ancient Greece, in Lutheran liturgy, in Italian theory of music); (b) some detailed examination about the topic of passions in German baroque treatises; (c) a review regarding evolution of the subject up to current discusses..