Word-specific tonal realizations in Mandarin
This research addresses a fundamental problem in linguistics by revealing that meaning influences tonal patterns in Mandarin, potentially impacting theories of speech production and perception, though it is incremental as it builds on prior work on articulatory constraints.
This study tackled the problem of understanding tonal realizations in Mandarin two-character words by showing that word meanings, not just previously known factors like speech rate or co-articulation, partially determine pitch contours, with computational models achieving 50% accuracy in predicting word type from pitch and 40% accuracy in predicting pitch from context-sensitive embeddings.
The pitch contours of Mandarin two-character words are generally understood as being shaped by the underlying tones of the constituent single-character words, in interaction with articulatory constraints imposed by factors such as speech rate, co-articulation with adjacent tones, segmental make-up, and predictability. This study shows that tonal realization is also partially determined by words' meanings. We first show, on the basis of a corpus of Taiwan Mandarin spontaneous conversations, using a generalized additive regression model, and focusing on the rise-fall tone pattern, that after controlling for effects of speaker and context, word type is a stronger predictor of tonal realization than all the previously established word-form related predictors combined. Importantly, the addition of information about meaning in context improves prediction accuracy even further. We then proceed to show, using computational modeling with context-specific word embeddings, that token-specific pitch contours predict word type with 50% accuracy on held-out data, and that context-sensitive, token-specific embeddings can predict the shape of pitch contours with 40% accuracy. These accuracies, which are an order of magnitude above chance level, suggest that the relation between words' pitch contours and their meanings are sufficiently strong to be potentially functional for language users. The theoretical implications of these empirical findings are discussed.