Starting from the finding that simultaneous interpreters have an increased number of stutter-like disfluencies in their speech when working through noise, the thesis sets out to explore the relationship between the stutters of normal speakers under stress and pathological stuttering. Since the conditions under which pathological stuttering can be suppressed, and in particular the absence of auditory feedback, appear to involve distraction from auditory feedback, it is hypothesised that attention to auditory feedback is important in pathological stuttering. The thesis is designed to determine whether this is also true of the stutters of normal speakers under stress, particularly interpreters. The role of stress is discussed in terms of its effects on attention deployment. It is proposed that the known attention narrowing effect of stress or high arousal may be operating to direct attention intermittently to auditory feedback in all types of stuttering, including delayed auditory feedback stuttering. Experiment 1 investigates the effect of reducing, amplifying, and delaying auditory feedback, and of speech tasks requiring different patterns of attention deployment, on the occurrence of stutters. The known effects of delayed auditory feedback are found. Interpreting elicits more stutters than shadowing, and a significant relationship is found between stutters and failures to attend to simultaneous task input. Experiment 2 is designed to elicit stutters in normal speakers by inducing anxiety and fluctuations of attention, using electric shocks and a divided-attention speech task. Anxiety does not increase stutters, hut there is some evidence that it increases attention to auditory feedback. The divided-attention task succeeds in increasing stutters, and a control condition of masked auditory feedback reduces stutters. It is concluded that attention to auditory feedback plays a role in the stutters of normal speakers, but only when attention is divided or fluctuating, and that these findings are consistent with the view that pathological and normal stutters are related.