Studying mandarin tone sandhi in interaction

The Mandarin low tone (T3) undergoes an alteration, third tone sandhi, when followed by another T3. The resulting F0 is superficially the same as that of the rising tone (T2) and has the potential to induce confusion. We investigated how Mandarin speakers adjust their speech production to overcome potential ambiguities induced by third tone sandhi during a structured interactive task. Ten pairs of L1 Chinese participants completed an interactive phrase matching task. Participants were shown displays with Chinese phrases (surname+title). One participant read an indicated phrase which the other selected from their display. There were two conditions. In the no sandhi condition, the title did not induce sandhi, and should result in distinct F0 patterns for the surnames. In the sandhi condition, the title induced third tone sandhi, and should result in homophonous surnames. Task performance showed clear evidence of sandhi-induced ambiguity. Examination of accuracy and tone acoustics suggested that pairs reduced sandhi-induced ambiguity primarily by lowering the F0 of T3 towards the end of its trajectory. We interpret this as avoidance of sandhi application. This study shows that even highly structured interactive tasks have potential to reveal new insights into how speakers and listeners navigate communicative ambiguities caused by tone sandhi. This constitutes an important first step to evaluating how phenomena such as tone sandhi generalize to everyday interactive communication.