The online effect of clash is durational lengthening, not prominence shift: Evidence from Italian

•Two production studies of clash with 24 native speakers of Italian in total.•Correlates of clash are duration and formant changes in the final vowel of word one.•Findings interpreted as changes to prosodic boundaries and/or gestural dynamics.•Two dynamical models of the observed changes in clash are presented.•Reported changes to prominence best interpreted as biased lexical selection.