* Heng and Deterding (2005) found that Singaporean English reduces a relatively low percentage of vowels to /ə/, with 45% of vowels being reduced compared to 100% for the British English control group for the tokens being analyzed. Because the incidence of /ə/ in Singaporean English is still high, it is important to test for this combination if possible, but it is unlikely that Singaporean English stop + /ə/ tokens can be reliably elicited from a word list. Instead, where available, relevant tokens from spontaneous production should be analyzed instead.
[Note: the paper came back from Lisa and Frans with a suggestion to test /ʌ/ if /ə/ could not be reliably solicited, since /ʌ/ is the stressed equivalent of /ə/ in General American. Singaporean English, however, has the phoneme /ɜ/ as the stressed equivalent of /ə/, which would be an even better test. /ʌ/-/ɜ/ is contrastive in Singaporean English, as in the minimal pair bud-bird.]
Given that Singaporean English is poorly defined and described, this study will compare children's production with their parents' production, rather than against a standard set of phonetic features. The parents’ production of these words will serve as a baseline result, allowing us to establish the phonemic distinctions in each of the three languages. If a set of parents shows statistically anomalous significant transfer effects from one language to another, the child’s results can be excluded or considered separately from the main participant pool.
The experiment will take place over two days for each of the groups in order to mitigate any potential priming effects from having both languages tested on the same day. On the first day, each child will be shown pictures designed to elicit the target words in English, in the carrier phrase “this is (a) ________”. If the child does not produce the word, delayed elicitation can be used to prompt the child to produce the word. This will be followed by a spontaneous five-minute conversation between the child and a native speaker of Singaporean English. On the second day, this procedure will be repeated with the other language (either Mandarin or Malay).
The parents will be individually tested in separate rooms at the same time as their child. On the first day, each parent will be given the list of target words in English and asked to read them aloud in the carrier phrase “I say ________”. This will be followed by a spontaneous five-minute conversation with a native speaker of Singaporean English. On the second day, this procedure will be repeated with the other language, with the conversation being carried out with a native speaker of the other language.
After the speech samples have been collected, they will be coded and analyzed with the aim of identifying how phonemic distinctions are codified in each of the three languages, and the extent to which each individual speaker was able to maintain distinct phonemic categories across both languages.
I expect the baseline results from the parents’ speech samples to show that for word-initial stops, Mandarin has an aspiration contrast, Malay has a voicing contrast, and Singaporean English has a VOT length distinction with aspiration accompanying longer VOT. It is also possible that Singaporean English has an aspiration contrast with optional voicing, or a voicing contrast with optional aspiration. I do not expect place of articulation or the subsequent vowel to have a significant effect on either the parents’ or children’s voicing, aspiration or VOT in word-initial stops.
Based on this, I would expect the SgE/Mandarin bilingual children to have acquired the aspiration contrast in Mandarin and the SgE/Malay bilingual children to have acquired the voicing contrast in Malay. I would expect both groups of children to have a VOT distinction in Singaporean English. If this is indeed the case, that would suggest that the phonological systems of bilingual children at age 4 are separate and distinct, with minimal transfer from one language to another. A phonemic category is not defined only its discrete segmental properties, but is linked to one language or the other in the mind of the speaker.
If the SgE/Mandarin and SgE/Malay children have different contrasts for word-initial stops in Singaporean English compared to their parents (for example, SgE/Malay children contrast voicing in English while SgE/Mandarin children contrast aspiration in English, while both SgE/Malay and SgE/Mandarin parents contrast VOT in English), that would suggest that there is interference from Mandarin or Malay in their acquisition of English. Conversely, if the SgE/Malay children have aspirated stops in their Malay production or if the SgE/Mandarin children have voiced stops in their Mandarin production, that would suggest interference from English in their acquisition of Malay or Mandarin. In either case, this result would indicate that the phonological systems of bilingual children are not kept completely separate, at least not at age 4.
These results would not necessarily answer the question of whether bilingual children begin the process of language acquisition with one or two phonological systems, only of whether they end the process of phonological acquisition with separate systems, and whether there is any interaction between the two systems at the end of phonological acquisition. To more accurately trace the development of phonological systems in bilingual children, a longitudinal study from first words to the end of phonological acquisition is necessary, but there are many methodological considerations that make such an undertaking difficult. For example, the linguistic environment of bilingual children is likely to vary much more widely than that of monolingual children, making direct comparisons between children problematic. Additionally, in the earliest stages of speech production, before individual segments are fully acquired, it is difficult to ascribe utterances to one language or another.
One more possibility must be considered: if there is a significant effect of language pair on stop distinctions in English among the parents (i.e. SgE/Mandarin and SgE/Malay parents have different stop distinctions in English), that points to a larger question that cannot be adequately answered in this study: dialectal variation in a language as a direct result of the great majority of its native speakers being bilingual in other languages.
Other potential follow-up studies include a perception study to see if bilingual Singaporean children and adults accurately perceive voiceless aspirated, voiceless unaspirated and voiced stop distinctions depending on their own native languages and the language being spoken (for example, can an SgE/Malay speaker accurately perceive the difference between /ph/ and /p/ in both Mandarin and English?) Additionally, if a similar production study could be replicated in other areas where simultaneous bilingualism is common, such as Quebec, Catalonia or Hong Kong, it could be determined whether the result obtained in the Singapore context is specific to the linguistic situation in Singapore, or if bilingual children as a group maintain separate or merged phonological systems in their two native languages, regardless of what those languages are.
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