Two experiments are reported which suggest that a dynamic memory updating task, running memory, requires two independent mechanisms — the articulatory loop and a component of the central executive. Experiment 1 shows that irrelevant speech and articulatory suppression impair the serial recall component of the running memory task but not the updating component. Updating memory affects performance independently of the effects of irrelevant speech and suppression. The second experiment produced the same pattern of results with a close to span memory load. These results are interpreted in terms of the working memory model outlined by Baddeley (1986). It is concluded that the updating of working memory in real time is coordinated by a central executive component of the model.