Interruptibility of Speech

Abstract

We have conducted a preliminary set of experiments on the ability of a speaker to interrupt himself when given a cue to do so at unexpected moments. Subjects were asked to repeat short utterances, each containing only one primary stress, at a fixed rhythm determined by a metronome. Contrary to our expectations, we did not find any particular point in these utterances when a speaker finds it harder to stop saying what he originally intended to say and start saying something else instead. Subjects were able to respond about 350 msec after the presentation of the cue (a 1-kHz tone), irrespective of where in the utterance the cue was presented. But when the cue was presented not within but just before the utterance, subjects took far longer (up to 750 msec) to respond. It is hypothesized that while a speaker is planning the articulations for a short utterance (in this case a single stress group), there is a period during which he cannot readily plan another utterance. [Research supported by ONR.]