  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 Taiwan corpus
of spontaneous conversations, using the 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 pitch 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 30% 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 functional for language users. The
theoretical implications of these empirical findings are discussed.
