Sensorimotor processing in speech examined in automatic imitation tasks

The origin of humans’ imitative capacity to quickly map observed actions onto their motor repertoire has been the source of much debate in cognitive psychology. Past research has provided a comprehensive account of how sensorimotor associative experience forges and modulates the imitative capacity underlying familiar, visually transparent manual gestures. Yet, little is known about whether the same associative mechanism is also involved in imitation of visually opaque orofacial movements or novel actions that were not part of the observers’ motor repertoire. This thesis aims to establish the role of sensorimotor experience in modulating the imitative capacity underlying communicative orofacial movements, namely speech actions, that are either familiar or novel to perceivers. Chapter 3 first establishes that automatic imitation of speech occurs due to perception- induced motor activation and thus can be used as a behavioural measure to index the imitative capacity underlying speech. Chapter 4 demonstrates that the flexibility observed for the imitative capacity underlying manual gestures extends to the imitative capacity underlying visually perceived speech actions, suggesting that the associative mechanism is also involved in imitation of visually opaque orofacial movements. Chapter 5 further shows that sensorimotor experience with novel speech actions modulates the imitative capacity underlying both novel and familiar speech actions produced using the same articulators. Thus, findings from Chapter 5 suggest that the associative mechanism is also involved in imitation of novel actions and that experience-induced modification probably occurs at the feature level in the perception-production link presumably underlying the imitative capacity. Results are discussed with respect to previous imitation research and more general action-perception research in cognitive and experimental psychology, sensorimotor interaction studies in speech science, and native versus non-native processing in second language research. Overall, it is concluded that the development of speech imitation follows the same basic associative learning rules as the development of imitation in other effector systems

The listening talker: A review of human and algorithmic context-induced modifications of speech

International audienceSpeech output technology is finding widespread application, including in scenarios where intelligibility might be compromised - at least for some listeners - by adverse conditions. Unlike most current algorithms, talkers continually adapt their speech patterns as a response to the immediate context of spoken communication, where the type of interlocutor and the environment are the dominant situational factors influencing speech production. Observations of talker behaviour can motivate the design of more robust speech output algorithms. Starting with a listener-oriented categorisation of possible goals for speech modification, this review article summarises the extensive set of behavioural findings related to human speech modification, identifies which factors appear to be beneficial, and goes on to examine previous computational attempts to improve intelligibility in noise. The review concludes by tabulating 46 speech modifications, many of which have yet to be perceptually or algorithmically evaluated. Consequently, the review provides a roadmap for future work in improving the robustness of speech output

Recognizing Speech in a Novel Accent: The Motor Theory of Speech Perception Reframed

The motor theory of speech perception holds that we perceive the speech of another in terms of a motor representation of that speech. However, when we have learned to recognize a foreign accent, it seems plausible that recognition of a word rarely involves reconstruction of the speech gestures of the speaker rather than the listener. To better assess the motor theory and this observation, we proceed in three stages. Part 1 places the motor theory of speech perception in a larger framework based on our earlier models of the adaptive formation of mirror neurons for grasping, and for viewing extensions of that mirror system as part of a larger system for neuro-linguistic processing, augmented by the present consideration of recognizing speech in a novel accent. Part 2 then offers a novel computational model of how a listener comes to understand the speech of someone speaking the listener's native language with a foreign accent. The core tenet of the model is that the listener uses hypotheses about the word the speaker is currently uttering to update probabilities linking the sound produced by the speaker to phonemes in the native language repertoire of the listener. This, on average, improves the recognition of later words. This model is neutral regarding the nature of the representations it uses (motor vs. auditory). It serve as a reference point for the discussion in Part 3, which proposes a dual-stream neuro-linguistic architecture to revisits claims for and against the motor theory of speech perception and the relevance of mirror neurons, and extracts some implications for the reframing of the motor theory

Models and analysis of vocal emissions for biomedical applications

This book of Proceedings collects the papers presented at the 3rd International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications, MAVEBA 2003, held 10-12 December 2003, Firenze, Italy. The workshop is organised every two years, and aims to stimulate contacts between specialists active in research and industrial developments, in the area of voice analysis for biomedical applications. The scope of the Workshop includes all aspects of voice modelling and analysis, ranging from fundamental research to all kinds of biomedical applications and related established and advanced technologies

The role of imitation in learning to pronounce.

Timing patterns and the qualities of speech sounds are two important aspects of pronunciation. It is generally believed that imitation from adult models is the mechanism by which a child replicates them. However, this account is unsatisfactory, both for theoretical reasons and because it leaves the developmental data difficult to explain. I describe two alternative mechanisms. The first explains some timing patterns (vowel length changes, 'rhythm', etc.) as emerging because a child's production apparatus is small, immature and still being trained. As a result, both the aerodynamics of his speech and his style of speech breathing differ markedly from the adult model. Under their constraints the child modifies his segmental output in various ways which have effects on speech timing but these effects are epiphenomenal rather than the result of being modelled directly. The second mechanism accounts for how children learn to pronounce speech sounds. The common, but actually problematic, assumption is that a child does this by judging the similarity between his own and others' output, and adjusting his production accordingly. Instead, I propose a role for the typical vocal interaction of early childhood where a mother reformulates ('imitates') her child's output, reflecting back the linguistic intentions she imputes to him. From this expert, adult judgment of either similarity or functional equivalence, the child can determine correspondences between his production and adult output. This learning process is more complex than simple imitation but generates the most natural of forms for the underlying representation of speech sounds. As a result, some longstanding problems in speech can be resolved and an integrated developmental account of production and perception emerges. Pronunciation is generally taught on the basis that imitation is the natural mechanism for its acquisition. If this is incorrect, then alternative methods should give better results than achieved at present

Investigating the build-up of precedence effect using reflection masking

The auditory processing level involved in the build‐up of precedence [Freyman et al., J. Acoust. Soc. Am. 90, 874–884 (1991)] has been investigated here by employing reflection masked threshold (RMT) techniques. Given that RMT techniques are generally assumed to address lower levels of the auditory signal processing, such an approach represents a bottom‐up approach to the buildup of precedence. Three conditioner configurations measuring a possible buildup of reflection suppression were compared to the baseline RMT for four reflection delays ranging from 2.5–15 ms. No buildup of reflection suppression was observed for any of the conditioner configurations. Buildup of template (decrease in RMT for two of the conditioners), on the other hand, was found to be delay dependent. For five of six listeners, with reflection delay=2.5 and 15 ms, RMT decreased relative to the baseline. For 5‐ and 10‐ms delay, no change in threshold was observed. It is concluded that the low‐level auditory processing involved in RMT is not sufficient to realize a buildup of reflection suppression. This confirms suggestions that higher level processing is involved in PE buildup. The observed enhancement of reflection detection (RMT) may contribute to active suppression at higher processing levels

Integration of Action and Language Knowledge: A Roadmap for Developmental Robotics

“This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." “Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.”This position paper proposes that the study of embodied cognitive agents, such as humanoid robots, can advance our understanding of the cognitive development of complex sensorimotor, linguistic, and social learning skills. This in turn will benefit the design of cognitive robots capable of learning to handle and manipulate objects and tools autonomously, to cooperate and communicate with other robots and humans, and to adapt their abilities to changing internal, environmental, and social conditions. Four key areas of research challenges are discussed, specifically for the issues related to the understanding of: 1) how agents learn and represent compositional actions; 2) how agents learn and represent compositional lexica; 3) the dynamics of social interaction and learning; and 4) how compositional action and language representations are integrated to bootstrap the cognitive system. The review of specific issues and progress in these areas is then translated into a practical roadmap based on a series of milestones. These milestones provide a possible set of cognitive robotics goals and test scenarios, thus acting as a research roadmap for future work on cognitive developmental robotics.Peer reviewe

Perception and production of syllable structure and stress by adult Libyan Arabic speaker acquiring English in the UK

The field of second language (L2) phonology has recently addressed the related phonological acquisition question of to what extent exposure to native speaker L2 input following exposure to non-native accented L2 input, results in c~anges in the leamer's interlanguage phonology (Akita 2001). If such learners do show changes over time, what kind of changes are these in both perception and production? My study is a contribution to interlanguage studies on the acquisition of prosodic structure, and concentrates on the acquisition of English syllable structure and metrical stress by Arabic speaker. In this study the interlanguage phonology of 28 native Arabic speakers from Libya learning English in natural settings (The UK), was investigated. The average age of the participants was 32.5 years. All the subjects started learning English in school at an average age of 16.0 years. The primary source oflanguage input was the classroom, till an average age of25.0 years. The method of collecting data involved three types of test. The first test covered syllable structure in onset and coda with epenthesised forms and included 185 words. The second test covered metrical stress, and included two sub-tests. Test 2A included 28 words, and test 2B included 84 sentences with grammatical and ungrammatical forms of stress. The third test contained three sub-tests. Test 3A included 9 words, test 3B included four pictures, and test 3C included 28 sentences. Tests cover perception of syllable structure and metrical stress as well as production of syllable structure and metrical stress for each learner. In the perception test learners had to listen to a type and chose an answer from a paper in front of them whereas for production tests learners had to read words, sentences, and talk about pictures. Their production output was recorded and transcribed. Results show differences for the perception and production sub-tasks. There is also some parameter resetting and missetting at the level of metrical stress. These results mirror the findings of Archibald (1993) Pater (1997) and Mousa (1994).EThOS - Electronic Theses Online ServiceGBUnited Kingdo