Prosody, voice assimilation, and conversational fillers

Conversational fillers (CFs), commonly transcribed as uh, um, or er, typically start with a schwa-like vowel, and signal multiple social, interactive, meta-cognitive, and pragmatic functions. They also co-occur with prosodic boundaries, increase saliency of inter-word disjunctures, and participate thus in coding the prosodic structure. Contrary to these functions, CFs are assumed not to participate in the phonological system of a language. This paper uses two types of Slovak conversational speech corpora for investigating the prosodic and phonological behavior of CFs. In Slovak, the vowel inventory does not include a schwa, and word-final obstruents undergo voice assimilation that is triggered by word-initial vowels but interacts with the strength of the prosodic boundary between the two words. Our data show the propensity of CFs to neutralize word-final voicing, and function thus as prosodic breaks, but also non-negligible number of cases of CFs triggering voicing of word-final obstruents, supporting their relevance for cognitive phonology.