Towards a definition of schwa : an acoustic investigation of vowel reduction in English
This thesis reports a single speaker acoustic study of vowel variability in connected speech. Over eight thousand vowel tokens taken from a corpus of read sentences are examined. The aim of the thesis is to achieve a better understanding of the nature of vowel reduction in English. Three questions are addressed. The first of these concerns the phonetic characterisation of schwa, the central or 'reduced' vowel. Schwa's contextual variability is assessed with reference to the question of whether or not it has an independent phonetic target. The second question concerns the role of stress in conditioning vowel reduction. Patterns of variability for sententially stressed and unstressed vowel tokens are examined in order to determine how far stress and context effects interact to influence vowel quality. The final question concerns the potential ditf erences between vowels with respect to inherent variability, that is, whether some vowels are inherently more susceptible to coarticulatory effects than other vowels. Maximal context-dependency for schwa strongly supports the hypothesis that it is completely unspecified for tongue position. The data indicate that it is also highly unspecified for jaw position. Evidence
Bates, Sally Alexandra Rosemary
Linguistics
Towards a definition of schwa : an acoustic investigation of vowel reduction in English. This thesis reports a single speaker acoustic study of vowel variability in connected speech. Over eight thousand vowel tokens taken from a corpus of read sentences are examined. The aim of the thesis is to achieve a better understanding of the nature of vowel reduction in English. Three questions are addressed. The first of these concerns the phonetic characterisation of schwa, the central or 'reduced' vowel. Schwa's contextual variability is assessed with reference to the question of whether or not it has an independent phonetic target. The second question concerns the role of stress in conditioning vowel reduction. Patterns of variability for sententially stressed and unstressed vowel tokens are examined in order to determine how far stress and context effects interact to influence vowel quality. The final question concerns the potential ditf erences between vowels with respect to inherent variability, that is, whether some vowels are inherently more susceptible to coarticulatory effects than other vowels. Maximal context-dependency for schwa strongly supports the hypothesis that it is completely unspecified for tongue position. The data indicate that it is also highly unspecified for jaw position. Evidence
towards definition acoustic investigation vowel reduction english report single speaker acoustic study vowel variability connect_speech thousand vowel tokens take corpus read sentence examine aim_achieve good nature vowel reduction english question_address first_concern phonetic characterisation central reduced vowel contextual variability assess reference question_whether independent phonetic target second question_concern role stress condition vowel reduction patterns variability stress vowel token examine order_determine far stress context effect interact influence vowel quality final question_concern potential vowel respect inherent variability whether vowel inherently susceptible effect vowel maximal context dependency strongly support_hypothesis completely unspecified tongue position data_indicate also_highly unspecified position evidence