Uh, um and mh: Are filled pauses prone to conversational converge?

Filled pauses are very frequent words, such as uh, um or mh in English. They have been shown to serve many purposes in interaction management, yet whether these conversational functions are intended by the speaker to ease the interaction (heareroriented) or just interpretations by the interlocutor of otherwise unintentional vocalizations (speaker-oriented) remains an open question. To participate in this debate, we investigate whether filled pauses converge in terms of form (uh, um or mh) in the course of 5 conversations made up of 12 asymmetrical subconversations. Results show that each conversation displays a different pattern in the choice of the filled pause, yet none of them shows any clear evidence that participants align with their interlocutors. This indicates that, unlike other frequent words from the lexicon, filled pauses do not converge, at least in their form, and that their use is more likely speaker-oriented than hearer-oriented.