Investigation of Validity of Paradigmatic Diagnosis for Downstep in Japanese*

This study investigates the validity of paradigmatic diagnosis for downstep in Japanese and seeks to ascertain whether downstep is directly triggered by accents or not. The paradigmatic diagnosis of downstep in Japanese claims that if the pitch height of X is lower after an accented word (A) than after an unaccented word (U), X is downstepped. However, the F0 differences between the AX and UX sequences before X may affect the F0 difference at X. Furthermore, if a phonological boundary results in another downtrend, it is crucial to control the phonological phrasing in order to accurately assess the isolated effect of downstep. Eight native speakers of Tokyo Japanese participated in a production experiment, which paradigmatically compared (A)(X) with both single domain (UX) and separated domains (U)(X). Our results yield two notable findings. First, we observed a more pronounced F0 rise in the downstep conditions than in the non-downstep conditions. Second, the paradigmatic F0 difference between AX and UX between AX and UX decreases when X is boosted. These findings suggest that downstep is triggered by phonological boundaries, not by accents.