Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 96-99).

abstract / Speech and Hearing Sciences / Master / Master of Philosophy

No description available.

Thesis--Wisconsin. / Includes bibliographical references (leaves 68-70).

Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 78-84).

Thesis (B.Sc)--University of Hong Kong, 2002. / "A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, May 10, 2002." Also available in print.

During the time when a child learns the sound system of his language, there is much evidence that the child can perceive phonological distinctions and therefore detect phonetic differences before he can produce these distinctions. This evidence is often provided to disprove the hypothesis that the child could be using an "active" model of speech perception. One such model, the analysis by synthesis model of speech perception, supposes that decoding of the acoustic signal employs the articulatory representation that would be required to produce the hypothesized identity of the incoming signal. The model proposes that while the human auditory system is innately equipped to handle the segments contained in speech, that the correlations between the acoustic information and articulation are learned with experience and form the basis for the division of the continuous acoustic signal into discrete categories of speech sounds. This thesis reviews recent research into the speech perception process and revises the analysis by synthesis model. It reveals that the human auditory system is innately equipped to divide stimuli (both speech and non-speech) that vary along certain acoustic dimensions into discrete classes. The unique processing that results for speech stimuli, occurs when the stimuli is recognized as having a function in the system of language. Hence the requirements for phonetic processing involve the psychological realization that stimulus originated in the human vocal tract. This investigation then reviewed the available literature on the perception and production of children acquiring language to determine whether there is support for their use of the revised analysis by synthesis model. The results favoured that children do use such a model. When resolving the various acoustic cues that combine to form a stimulus complex, the child does refer to his articulatory abilities. Lacking full articulatory knowledge, the perceptual errors that typify children's language, occur. It was shown that the child need not have the precise adult articulatory configuration in order to utilize this model. The model is operative during the child's perception of both himself and the adult. In both instances the comparator performs the function of matching the child's articulatory representation with his perceived representation of a form. The results serve to improve his knowledge of acoustic-articulatory correlations. In this manner the processes of perception and production are closely integrated and as understanding of their fine interrelationship improves, production becomes more accurate and perception is simplified. / Medicine, Faculty of / Audiology and Speech Sciences, School of / Graduate

Previous research (Werker, Gilbert, Humphrey, & Tees, 1981) in which we compared English infants, English adults, and Hindi adults on their ability to discriminate two pairs of Hindi (non-English) speech contrasts indicated that infants without prior specific language experience can discriminate speech sounds according to phonetic categories, whereas adults may lose this ability as a function of either age and/or specific language experience. The present work was designed to answer several questions that emerged from that earlier research. First, experiments focussed on delineating the time course of the "decline" in non-native speech discrimination abilities across childhood. Second, experiments examined the generality of developmental change between infancy and adulthood by looking at cross-language speech perception of a new (Thompson, an Interior Salish Native Indian Language) non-English speech contrast. Third, speech perception performance was examined in relation to cognitive and linguistic development to try to determine why the decline occurred at one rather than another point in ontogeny. Finally, an attempt was made to clarify the nature and implications of the apparent loss of non-native speech perception abilities by varying both the discrimination procedure and the perceptual set conditions used in adult testing. The results of these experiments replicate our original findings (Werker, et. al., 1981) showing that infants can discriminate the universal set of phonetic contrasts, and that there is a decline in this ability as a result of specific linguistic experience. This decline occurs within the first year of life. The data tentatively support the notion that a certain level of memory development (enabling an early form of representational ability) may be necessary before specific experience can modify initial infant abilities. In addition, the results show a difference between phonetic and phonemic (meaning based) perception in adult subjects, with the phonemic being the most robust and the most easily demonstrated. It is suggested that phonemic perception may reflect the structuring of cognitive/perceptual categories. Speculation as to the form (prototypical) and the format (initially enactive, later symbolic) of the representation of these categories is offered. / Arts, Faculty of / Psychology, Department of / Graduate

Note:

The developmental process of audiovisual speech perception was examined in this experiment using the McGurk paradigm (McGurk & MacDonald, 1976), in which a visual recording of a person saying a particular syllable is synchronized with the auditory presentation of another syllable. Previous studies have shown that audiovisual speech perception in adults and older children is very influenced by the visual speech information but children under five are influenced by the auditory input almost exclusively (McGurk & MacDonald, 1976; Massaro, 1984; and Massaro, Thompson, Barron, & Laren, 1986). In this investigation 46 children aged between 4:7 and 12:4, and 15 adults were presented with conflicting audiovisual syllables made according to the McGurk paradigm. The results indicated that the influence of auditory information decreased with age, while the influence of visual information increased with age. In addition, an adult-like response pattern was observed in only half of the children in the oldest child subject group (10-12 years old) suggesting that the integration of auditory and visual speech information continues to develop beyond the age of twelve.