Error monitoring in speech production: A computational test of the perceptual loop theory

A theory of speech monitoring, proposed by Levelt (1983), assumes that the quality of one's speech is checked by the speech comprehension system. This system inspects one's own overt speech but would also inspect an inner spe ech plan ("the inner loop"). We have elaborated and tested this theory by w ay of formalizing it as a computational model. This model includes a new pr oposal concerning the timing relation between planning the interruption and the repair: the proposal that these two processes are performed in paralle l. We attempted to simulate empirical data about the distribution of error- to-cutoff and cutoff-to-repair intervals and the effect of speech rate on t hese intervals (these intervals are shorter with faster speech). The main q uestions were (1) Is an inner monitor that utilizes the speech perception s ystem fast enough to simulate the timing data? (2) Can the model account fo r the effects of speech rate on these intervals? We conclude that including an inner loop through the speech comprehension system generates prediction s that fit the empirical data. The effects of speed can be accounted for, g iven our proposal about the time course of planning interruption and repair . A novel prediction is that the error-to-cutoff interval decreases with in creasing position in the phrase, (C) 2001 Academic Press.