Abstract
We investigated whether syntactic complexity affects filler rate at phrase boundaries in Japanese presentation speeches. We examined filler rate immediately after dependent phrases (i.e., 'bunsetsu') as a function of the distance to their heads (measured as the number of intervening phrases). The filler rate monotonically increased with the distance, regardless of speaker's gender and presentation type. The results indicate that filler rate reflects speakers' cognitive load of grammatical encoding of a message. When we examined the rates of four frequent filler types, "ano", "e", "eto" and "ma", separately, we found that use of the four filler types differs depending on speaker's gender and presentation type. The results suggest that speakers need more time to formulate longer phrases and consequently are more likely to utter fillers in general, but that the choice of filler type is affected by speaker's gender and speech style.
