The theme/rheme distinction: Accent type or relative prominence?

In English, theme/rheme status (or topic/comment) is claimed to be marked by pitch accent type, i.e. L+H⁎ (LH%) versus H⁎ (LL%). Calhoun (2010a) claims that, rather, themes are relatively less prominent than rhemes. The phonetic realisation of themes and rhemes was looked at in a semi-spontaneous game task, e.g. (following Will the banana land on some money?) No, the lollipop (rheme) will land on some money (theme), the banana (theme) will land on a monster (rheme). There were some phonetic differences consistent with an accent type difference: the preceding L pitch elbow, and the H peak, of (L+)H⁎ accents were later and lower on themes than rhemes. Themes also had a high boundary (LH%, HH% or H-) more often. However, these differences were small and not consistent. On the other hand, there were large and consistent differences in the relative prominence of paired themes and rhemes (e.g. lollipop and money). In theme–rheme order, the rheme f0 peak was slightly higher, whereas in rheme–theme order, it was substantially higher. The f0 peaks of paired themes and rhemes were also highly correlated. There were smaller differences in mean intensity and duration. This is clear support for Calhoun's claim that relative prominence marks the theme/rheme distinction, and for the importance of metrical prominence in signalling information structure.

► In English, it is claimed themes marked by L+H⁎ accents, versus H⁎ for rhemes. ► Calhoun, 2010a and Calhoun, 2010b claims actually themes less relatively prominent than rhemes. ► Semi-spontaneous game task used to investigate theme/rheme marking. ► Results showed strong phonetic evidence for relative prominence distinction. ► Shows metrical prominence, not accent type, signals information structure.