Supplementary Material for: No Acoustic Correlates of Grammatical Class: A Critical Re-Examination of Sereno and Jongman (1995)

The present article describes an extended replication of a reading study by Sereno and Jongman (1995) that reported acoustic differences between noun and verb pronunciations of English disyllabic, non-stress-shifting homophone pairs, for example, <i>answer</i> (v) versus <i>answer</i> (n). The original findings point to a gradual influence of the typical stress patterns of both grammatical categories, with noun readings exhibiting a tendency toward trochaic and verb readings toward iambic pronunciation. However, the effects found by Sereno and Jongman (1995) did not consistently reach statistical significance and were based on a very small sample size. Employing a considerably larger group of speakers, the current replication fails to find the reported effects of the grammatical category. The null result obtained can be accounted for within speech production models that assume identical metrical templates for the homophone pairs tested and no direct influence of the grammatical category on the phonetics of stress assignment.