The effect of boundary strength on focus realization

In Putonghua, single focus is realized with on-focus F0 raising and Post-Focus-Compression (PFC), whereas the first focus in a dual focus sentence shows limited PFC. Will prosodic boundary strength after a focused word affect focus realization, especially PFC? In this study, corresponding to syntactic word, phrase, clause and sentence boundaries, four degrees of prosodic boundary strength were designed after the critical word (X). The four focus conditions were elicited by preceding questions, i.e., on word (X), final word (Y), both X and Y(dual focus), and neutral focus. The acoustic analysis showed that (1) Focus words showed F0 raising and duration lengthening, with no significant difference between single and dual focus conditions, and with no difference among all the boundary conditions; (2) PFC after the first focus in dual focus sentences was weakened by a medium boundary, whereas PFC of a single focus was weakened by a very strong boundary; (3) Pre-boundary lengthening was increased as the boundary strength became stronger, however, there was an upper limit of the lengthening. The pre-boundary lengthening was not affected by focus locations. In general,boundary and focus were encoded in parallel in intonation.