Developmental Apraxia of Speech With Particular Reference to Aspects of Voicing

[摘要] Developmental apraxia of speech is a disorder which has given rise to much controversy, both in terms of its etiology and its clinical management. It has traditionally remained an ill defined concept, with an associated terminology which at times lacks clarity and precision. In the absence of unanimity amongst clinicians as to its nature, therapeutic programmes for its alleviation have been developed slowly and not always effectively. The aim of this thesis is to focus on one particular feature of the condition, namely the apraxic child's control of the timing mechanism for voicing. The experimental investigation is prefaced by a consideration of the varying approaches to developmental apraxia of speech from the 19th century onwards, noting the significance of studies of 'idioglossia' and, in the present century, the work of Orton in the United States and Morley in the United Kingdom. Notice is taken of the apparent inadequacies in the assessment and treatment programmes for the condition, which have culminated in some instances in practices which lack any firm theoretical foundation. Auditory and instrumental phonetic techniques are employed to elucidate the nature of the laryngeal timing deficiency in the condition, and the conclusion is reached that a possible source of this deficiency may be found in the child's respiratory and laryngeal mechanisms. It is postulated that developmental apraxia of speech should be viewed as part of a wider apraxic syndrome. By emphasizing, as a number of researchers have done for nearly 20 years, the role that phonology, rather than phonetics, can play in describing speech disorders, the opportunity has been lost to examine the underlying physiological mechanisms of speech production. In this study, the focus is firmly on articulation as physiology rather than phonology.

[发布机构] University:University of Glasgow

[关键词] Neurosciences, Speech therapy