Testing the applicability of third tone sandhi at the intonation boundary

The purpose of this study is to test the applicability of Tone Three Sandhi (T3S) when the critical syllable is a monosyllabic topic preceding a topic boundary. A recitation task from 37 native speakers of Taiwan Mandarin was employed. The results from human judgements indicated that the participants predominantly produced the critical syllables with Tone 3 (T3). Additionally, the fundamental frequency of the critical syllables demonstrated a falling contour, showing that T3S was not applied. Intonation break-ups and the prolongation of the critical syllables lent strong support to the view that the topic syllable was at an intonation/phonological phrase-final position. The findings can be elegantly accommodated by constraint-based analyses, which propose that T3S must be avoided when two T3 syllables are separated by an intonation/phonological phrase boundary. Issues relating to pauses, speech rates and word frequency effects are also discussed.