The Effects of Social and Experiential Factors on the Interactions between the Phonetic Systems of Diglossic Bilinguals

In diglossic contexts, when speakers typically use two different languages on a regular basis, bilingual speakers display a wide array of attitudes towards each of their languages and associated cultures (Galindo, 1995) and such variability in attitudes can affect their linguistic behaviors (Lambert, Hodgson, Gardner & Fillenbaum, 1960). However, the effect of attitudinal factors on bilingual phonetic interactions, especially at the suprasegmental level, is still largely unexplored, perhaps because researchers (used to working with immigrant populations who are more serially bilingual) have focused mainly on the effects of language learning-related conditions such as age of arrival in an L2-speaking country (MacKay, Flege, Piske & Schirru, 2001). In a diglossic society, these factors are more homogeneous, potentially revealing the subtler influence of attitudes on phonetic structures. Therefore, two experiments were designed to investigate how social and experiential factors may affect the interaction between the phonetic systems of bilingual speakers at the segmental and suprasegmental levels. Native Cantonese-English bilinguals living in Hong Kong participated in these two experiments. In both experiments, participants produced near homophones in each language on separate days. Consistent with the diglossic nature of Hong Kong, participants learned Cantonese (L1) from birth and English (L2) since age 2–3. Given this homogeneity in age- and input-related factors, the effects of attitudes towards each language and culture, language proficiency, and amount of use of each language (as elicited in a detailed questionnaire) were examined. Acoustic properties of segmental and suprasegmental speech sounds were measured in each language. These included formant frequencies of similar sounds across languages, and measures of speech rhythm (pairwise variability index, Low et al., 2000) and lexical tone and stress (fundamental frequency slope and range). Analysis suggests that in contrast to the conventional view that cross-linguistic interactions are purely mechanical and immutable consequences of language proficiency and use, bilingual speakers with a more positive attitude towards their first language (Cantonese) showed divergence between their two languages at both the segmental and suprasegmental levels. In contrast, the speakers’ attitudes towards English (L2) were not found to have a discernible effect on any acoustic properties measured. As for experiential factors, the speakers’ English (L2) proficiency and use were not found to have an observable effect on the three pairs of cross-language similar sounds investigated. However, higher English proficiency and use were found to modulate convergence of cross-language speech rhythm. Taken together, these results suggest that diglossic bilinguals with more partisan attitudes towards their L1 show more resistance to the influence of L2 on L1 at both the segmental and suprasegmental levels. On the other hand, the effect of L2 proficiency and use on cross-linguistic interactions in bilingual speakers depends on whether separate phonetic categories have been formed for the speech properties concerned. Participants produced divergence between lexical tone and stress but convergence of cross-language speech rhythm probably because these bilingual speakers have developed separate phonetic categories for lexical tone and stress but not for cross-language speech rhythm