An experimental investigation of the modifiability of the temporal structure of spontaneous speech.

This study attempted to test the hypothesis that the temporal structure of spontaneous speech is modifiable by reinforcing and punishing pauses, of a certain duration, in an operant conditioning situation. Pause rate was significantly affected by these contingencies: moreover, rate of change was rapid, indicating a "prepared" association between pausing and such contingencies. This study also attempted to test the hypothesis that there is a class of noncognitive pauses in monologue by punishing UPs to determine if UPs can be eliminated without affecting speech content. Although this manipulation did lead to a decline in pause rate, a significant increase in the amount of filled hesitation, particularly in repetition, resulted. This suggests that the overall amount of hesitation is fixed by the cognitive demands of the task but that a speaker is able to adapt to different interactional contexts by varying the category of hesitation used for cognitive planning.