ความสัมพันธ์ระหว่างการรับรู้เสียงพยัญชนะกักในภาษาไทยกับระดับความก้องในการเปล่งเสียงพยัญชนะกักในภาษาอังกฤษของผู้พูดภาษาอังกฤษเป็นภาษาแม่ / จิตราวดี สิงหนิยม = The relationship between the perception of Thai stops and the degree of voice-timing in the production of English stops by native speakers of English / Jitravadee Singhaniyom
This thesis attemps to examine the relationship between the perception of Thai stops and the degree of voice-timing in the production of English stops by 30 native speakers of English. For this purpose, the perception of initial voiceless unaspirated stops (UNASP) in Thai by these subjects and the voice-timing of the production of their initial English voiced stopds are examined. It is hypothesized that the degree of voice-timing in the production of English (L1) stops is the acoustic cue in the perception of Thai (L2) stops. Native speakers of English who perceive Thai UNASP as voiced stops will have devoiced stops in their production of voiced stops. The data is collected from 13 native speakers of British English (from the United Kingdom and Australia) and 17 native speakers of American English (from the United States of America and Canada) since literature review suggests that these two groups of subjects produce their voiced stops differently. The study of the perception of stops in Thai by these two groups of subjects shows that all of the subjects have no problems in perceiving voiceless aspirated stop and voiced stop in Thai. However, in their perception of voiceless unaspirated stops, the study reveals that all of the subjects who speak British English (13 subjects) perceive UNASP as voiced stops in English, 10 out of 17 subjects who speak American English perceive UNASP as voiceless stops in English, and the other 7 subjects who speak American English perceive UNASP as voiced stops in English. It is concluded that most of our subjects who speak two types of English perceive UNASP as voiced stops in English. The study of the production of English stops by these subjects reveals that most of the subjects who speak British English (11 from 13 subjects) have devoiced stops in their production of voiced stops, and the subjects who speak American English (15 from 17 subjects) also produce "devoiced stops" in their production of voiced stops. It is concluded that most of the 30 native speakers of English who are the subjects of this study devoiced their voiced stops. This study rejects the assumption that British and American English produce voiced stops differently. The study of the relationship between the perception of UNASP in Thai and the degree of voice-timing in the production of English stops reveals that there is a clear relationship between the perception and the production of stops in most of the subjects who speak British English (11 from 13 subjects) i.e., they perceive UNASP as voiced stops in English and produce their voiced stops as "devoiced". For the subjects who speak American English, it cannot be concluded clearly that there is a relationship between the perception of UNASP in Thai and the production of their voiced stops. Only one subject who speaks American English perceive UNASP in Thai as voiceless stops in English and produce his voiced stops as "fully voiced", another 6 subjects who speak American English perceive UNASP in Thai as voiced stops in English and produce their voiced stops as "devoiced" and the other 10 supjects perceive UNASP in Thai as voiceless stops in English and produce their voiced stops as "devoiced". The research reveals that if the perception of UNASP in Thai (L2) reflects the "prototype-phoneme" of voiced stops in English (L1). The speakers of British English, who are the subjects of this study, have the same prototype phoneme. But, the speakers of American English may have more than one prototype phoneme since there is a variation in their perception of UNASP in Thai. It is possible that the study of the production of English stops in initial position which is done in this study is not enough to represent the prototype phoneme of voiced stops in American English.
