Planning for the future and reacting to the present: Proactive and reactive F0 adjustments in speech

Previous studies have examined whether speakers initiate longer utterances with higher F0. Evidence for such effects is mixed and is mostly based on point estimates of F0 at the beginning of the utterance. Moreover, it is unknown whether utterance length can influence F0 control solely at utterance onset or also during the utterance. We conducted a sentence production task to investigate how control of pitch register – F0 ceiling, floor, and span – is influenced by utterance length. Specifically, we test whether speakers adjust register both in relation to an initially planned utterance length – proactive F0 control – and in response to changes in utterance length that occur after response onset – reactive F0 control. Target sentences in the experiment had one, two, or three subject noun phrases, which were cued with visual stimuli. An experimental manipulation was tested in which some visual stimuli were delayed until after participants initiated the utterance. Evidence for both proactive and reactive control of register was observed. Participants adopted a higher register ceiling and broader span in longer utterances. Furthermore, they decreased the amount of ceiling compression upon encountering delayed stimuli. The findings suggest the presence of a mechanism in which speakers continuously estimate the remaining length of the utterance and use that information to adjust pitch register.