Tonal Change Induced by Language Attrition and Phonetic Similarity in Hai-lu Hakka

This study examines the potential role of language attrition in the sound change of low-level tone in Hai-lu Hakka, and compares the change with similar tonal changes in Hong Kong Cantonese and Taiwan Southern Min (Taiwanese). The low-level tone changes to low-falling tone largely among young non-daily users, so the effect of language attrition led by a decline in frequency of use is hypothesized to be the main cause for the tonal change. To verify this hypothesis, three perception tasks and one production task were conducted on three groups of Hakka speakers: young non-daily users, young daily users and older daily users. The results show that: (i) non-daily users made significantly more tonal errors than daily users, (ii) the low-level tone was the least accurate category in all tasks and (iii) non-daily users were more likely to confuse low-level tone with low-falling tone in the production task than in the perception ones, indicating the effects of language attrition and phonetic similarity, and an asymmetry between perception and production processes. The findings suggest that the effects of language attrition reinforce the internal dynamics of phonetic similarity between low-level and low-falling tones, and result in sound change from the most confusing category to its counterpart that is similar in pitch height for minimizing articulatory efforts. Therefore, we claim that the ongoing tonal change is less likely to be an inevitable consequence resulting from Mandarin’s tonal influence via language contact, but an unfortunate outcome of Hai-lu Hakka’s attrition processes.