Native Language Perceptual Sensitivity Predicts Nonnative Speech Perception Differently in Younger and Older Singaporean Bilinguals

Abstract

Purpose: We investigate in this study how individual variability in native language speech perception (termed Perceptual Sensitivity ) influences nonnative speech perception in Singaporean Tamil–English bilinguals. Further, we assess if and how contextual and demographic factors influence Perceptual Sensitivity in the acquired languages and if the influence of Perceptual Sensitivity on nonnative speech perception is different across younger and older bilinguals. Method: Perceptual Sensitivity in the native languages was examined by implementing Tamil and English gating tasks in 87 Singaporean Tamil–English bilinguals from two age groups (younger: 19–33 years; older: 55–70 years). Mandarin lexical tone discrimination was implemented as a measure of nonnative speech perception. Results: There was a wide range of variability in Perceptual Sensitivity scores in both languages across both age groups. Perceptual Sensitivity in the first native language (L1 Tamil) was a robust predictor of nonnative speech perception across both age groups, especially for the older bilinguals. However, general intelligence emerged as a stronger predictor than Tamil Perceptual Sensitivity in younger bilinguals. The influence of Tamil Perceptual Sensitivity on lexical tone perception was not tone-specific, supporting a general enhancement of lexical tone perception with better Tamil Perceptual Sensitivity. There was an influence of demographic factors on English Perceptual Sensitivity in older bilinguals, but not for Tamil and not in younger bilinguals. Conclusions: Our findings corroborate with previous studies in showing that native language Perceptual Sensitivity is positively associated with and predicts nonnative speech perception in younger and older adulthood regardless of language similarity but to varying degrees. Specifically, the influence of Perceptual Sensitivity on nonnative speech perception is stronger in older adulthood, suggesting a possible shift in reliance on crystallized language knowledge with age. Proficiency and use, among other demographic and language variables, do not appear to influence L1 Perceptual Sensitivity in a lesser used language (Tamil) as significantly as previously assumed.

Exploring individual differences in native phonetic perception and their link to nonnative phonetic perception.

“…An additional possibility is that greater sensitivity to native speech sounds does promote better nonnative perception, but that this relationship emerges later in life. In line with this, Kalaivanan et al (2023) recently found that for older adults, native perceptual sensitivity (as measured by a gating task) was a robust predictor of nonnative discrimination; but for younger adults, general intelligence was a stronger predictor. Perhaps younger adults (like the participants in the present experiments) rely more on fluid cognitive factors including attention and memory, while older adults rely more on crystallized factors including their knowledge of native phonemes (Spreng & Turner, 2019).…”

“…Individuals with better discrimination of native vowels have been shown to have better identification of nonnative vowels on a 10-alternative forced-choice task (Lengeris & Hazan, 2010). Similarly, greater sensitivity to native contrasts on a gating task has been related to better discrimination of nonnative Mandarin tones (Kalaivanan et al, 2023). Other work suggests that having clearly defined, compact representations of a native vowel in psychoacoustic space predicts greater sensitivity to a nonnative vowel contrast (Kogan & Mora, 2022).…”