A priori information about the location of the target talker plays a critical'role in cocktailparty listening tasks, but little is known about the influence of imperfect spatial information in situations in which the listener has some knowledge about the location of the target speech but does not know its exact location prior to hearing the stimulus. In this study, spatial uncertainty was varied by adjusting the probability that the target talker in a multitalker stimulus would change locations at the end of each trial. The results show that listeners can adapt their strategies according to the statistical properties of a dynamic acoustic environment but that this adaptation is a relatively slow process that may require dozens of trials to complete.