Speech Production and the Predictability of Words in Context

The purpose of the experiments was to examine the function of hesitation pauses in speech. Pauses were conceived of as anticipating increase of information in subsequent speech and as involving acts of choice. This hypothesis was tested by relating the incidence of pauses within sentences to the transition probabilities of the words constituting them. Estimates of these probabilities were obtained experimentally by an adaptation of Shannon's guessing technique and were based on reverse as well as forward guessing. The hypothesis was borne out by the facts; hesitancy in speech was shown to be closely related to uncertainty of prediction (entropy) and fluency of utterance to redundancy. These results are shown to be in line with the facts of language statistics. Their theoretical implications for the concept of information and for understanding the processes of speech organization is discussed.