The productions of adult second language (L2) learners are often detected as having a foreign accent by native speakers of the target language. However, there is no clear answer for what kind of problems contribute to L2 learners’ foreign accent. This thesis aims to investigate potential factors behind foreign accent. We intend to achieve this goal by examining cross-linguistic empirical evidence of the L2 acquisition of Japanese lexical pitch accent by English learners. L2 prosody has been found to significantly influence native speakers’ auditory impression of foreign accent. L2 prosody also allows us to test crosslinguistic differences in the function of the key acoustic correlates of L2 contrasts. In this thesis we examine F0, which signals both lexical pitch accent and phrasal distinctions in Japanese, but which signals only phrasal distinctions, not lexical distinctions, in English. For adult L2 learners to achieve target-like productions, the literature suggests that three abilities are the key factors: 1) learners’ ability to differentiate the acoustic correlate of the target L2 contrasts, 2) ability to articulate the acoustic correlate of the target L2 contrasts and 3) ability to categorize the target L2 contrasts. This thesis evaluates all three of these potential factors. The main contribution of this thesis is to provide a comprehensive view of foreign accent, by investigating possible interactions between the factors and by examining the different abilities of the same learners. Another contribution is to provide empirical evidence for the nature of learners’ problems with foreign accent during L2 acquisition, by testing two groups of English learners of Japanese (experienced and inexperienced) in comparison with Japanese native speakers. The first experiment used intelligibility scores and overall F0 patterns to quantify the degree of foreign accent in the learners’ productions of Japanese lexical pitch accent. The second experiment showed that the learners’ ability to differentiate F0 contours in a nonspeech context was equal to that of the native speakers. The third experiment showed that the learners’ ability to articulate the F0 contours in a non-speech context differed from that of the native speakers. The fourth experiment showed that although learners were able to hear the phonetic differences between the target L2 contrasts, due to poor formation of the target L2 categories and poor lexical assignment ability, the inexperienced learners seem to have greater difficulty than experienced learners both in categorizing boundary items into the target L2 categories and in assigning the L2 categories to lexical items. Overall, the foreign accent of adult L2 learners’ productions is explained through a combination of articulation and categorization factors. Importantly, this cross-sectional study has indicated how learners’ problems with foreign accent change as they gain L2 experience. Whereas experienced learners seem to have problems mainly in the articulation and phonetic realization of the L2 contrasts, the inexperienced learners seem to have mainly problems in phonetic and lexical-phonological representations of the target L2 categories in addition to articulation and phonetic realization. This study offers both theoretical insights for the field of L2 speech acquisition research and also practical insights for the L2 classroom.

Made available in DSpace on 2016-04-28T18:23:36Z (GMT). No. of bitstreams: 1 sergio.pdf: 2431367 bytes, checksum: 49d6c74ea903d9d0c045da08226f295b (MD5) Previous issue date: 2008-02-11 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This dissertation aims at investigating the prosodic patterns in the speech of bilingual American and Brazilian speakers. By means of acoustic phonetic analysis, the manner by which speakers structure the prosodic groups was investigated in light of models that underscore the discoursal and attitudinal functions of intonation. Analyses were carried out on various strands: pitch configurations in idioms, distribution of pitch accents within an utterance whether it be for contrastive or emphatic reasons, and loss of accentual prominence in words that are no longer part of the common ground between speaker and listener. The study involved 4 female subjects, two Brazilians and two Americans, in the 20-40 age group. The corpus is comprised of 7 sentences in English and in Portuguese, four of which were uttered in the declarative modality, one in the exclamative modality and two in the interrogative modality. The sentences were extracted from a dialogue so constructed as to allow for the expression of attitudes and emotions. The dialogue was read and interpreted in three repetitions. The recordings of the readings were carried out at PUC-SP´s Radio and TV studio. The acoustic analysis of the data was done by means of the PRAAT software program, whereby utterances were segmented into units of varying sizes: GIPC, vowels, syllables and consonants. Results point to the use of language-specific strategies by Brazilian and American speakers: (a) Brazilians seem to favor a greater number of prosodic groups in order to maintain sentence focus at terminals; (b) speakers of both languages are heavily influenced by L1 intonational patterns in YES/N0 questions; (c) idioms as produced by non-natives present pitch configurations which convey attitudes incongruent with their meanings in the target language; (d) there are major distributional differences in the two languages as regards nucleus focus; (e) shared information is not a strong enough reason for deaccenting in Portuguese / Esta dissertação tem como objetivo investigar os padrões entoacionais de produções de falantes bilíngües norte-americanos e brasileiros. Por meio de instrumentais de análise fonético-acústica, foi investigado o modo pelo qual os falantes estruturam os grupos prosódicos, à luz de modelos de descrição da entoação que privilegiem o discurso e as atitudes. Foram analisadas as configurações de pitch em expressões idiomáticas, a distribuição do acento principal de pitch em enunciados em que ocorra contrastividade ou ênfase, e a perda (ou não) de proeminência acentual de palavras que já façam parte do conhecimento mútuo entre falante e ouvinte. O trabalho envolveu quatro sujeitos do sexo feminino na faixa etária entre 20 e 40 anos, sendo duas brasileiras e duas norte-americanas. O corpus é composto de 7 sentenças em inglês e em português, sendo 4 na modalidade declarativa, uma na exclamativa e 2 na interrogativa. As sentenças foram extraídas de um diálogo construído de modo a contemplar a expressão de atitudes e emoções. O diálogo foi lido e interpretado em três repetições. A gravação das leituras foi feita no Estúdio de Rádio e TV da PUC-SP. A análise acústica dos dados foi feita por meio do programa PRAAT, a partir da segmentação dos enunciados em unidades de tamanhos variados: unidades V-V, vogais, sílabas e consoantes. Os resultados obtidos apontam para o uso de estratégias diferenciadas por parte dos falantes brasileiros e norte-americanos: (a) falantes brasileiros tendem a fazer um maior número de fronteiras prosódicas, de modo a manter o acento frasal em fronteira final; (b) falantes de ambas as línguas tendem a sofrer influência dos padrões entoacionais de L1 nas questões totais; (c) A produção de expressões idiomáticas por falantes não nativos apresenta configurações de pitch que carreiam atitudes incompatíveis com seu significado em L2; (d) há diferenças nas duas línguas em relação à posição do acento frasal; (e) nem sempre informação já compartilhada pelos participantes do discurso perde a proeminência acentual no português