| Popis: |
Skilled perception of speech involves not just recognizing the words and sentences that a talker produces, but also perceiving properties imputed to the talker, such as being a foreigner. Because being perceived as foreign can have social consequences, it is important to understand the characteristics that contribute to this percept. Foreign accent perception is often studied in relation to talker characteristics, such as age of learning the second language (L2) or age of arrival in the L2-speaking country. However, listeners generally do not have direct access to such information. In order for the perception of foreign accent to be fully understood, it must be studied in relation to physical characteristics of the speech signal.This dissertation reports a series of six experiments that elicited American English monolinguals' ratings of various properties of productions from native talkers of American English, Hindi, Korean, Mandarin, and Spanish, as well as their free classifications of talker language background. In the first four experiments, listeners heard samples of English and rated foreign accentedness or non-nativeness for each production. In the final two experiments, listeners rated non-Englishness for samples of each talker producing his or her native language (L1). Linear mixed effects regression models revealed that VOT, F1 frequency, and F2 frequency correlated with ratings of accentedness and non-nativeness for syllable- and word-length stimuli. In addition, F3 frequency and F2 tilt correlated with the ratings for syllable-length stimuli, and vowel duration with the ratings for word-length stimuli. Non-Englishness ratings for word-length stimuli were closely related to listeners' ability to recognize the stimuli as known English words. Free classification results revealed that across listeners, grouping patterns for native talkers were more consistent than for most non-native talkers. The correlates of multidimensional scaling analyses of the free classification responses were similar to the correlates of the ratings.The results of this investigation reveal, for a varied sample of non-native English, which characteristics of the speech signal may lead American English monolinguals to identify a talker as foreign. When perceiving syllable-length stimuli, listeners seem to attend to phonetic details resulting from transfer from the non-native talker's L1, while indications of the talker's L2 fluency may begin to influence perception in units as small as disyllabic words. Such information may effectively identify priorities for L2 learners of English interested in accent reduction. |
