In this paper, we investigate the relationship between syntactic structures and boundary pitch movements (BPMs) of accentual phrases such as rising and rising-falling tones based on a quantitative analysis of spontaneous Jananese monologs. We found that BPMs tend to occur more frequently at syntactically and semantically deep boundaries, and also that the BPM rate at syntactically shallow boundaries tends to increase as the distance from the weak or non-clause boundary to its modified bunsetsu phrases increases. These results suggest that BPMs could have the function of indicating the continuation of the utterance. We also discuss the relationship between the occurrence of BPMs and cognitive load in speech planning.
