The authors examined the effects of response types and the presentation of auditory stimulus on motor inhibition. Continuous responding tasks were conducted with 27 younger adults and 39 older adults. The results indicated the following: (a) response type significantly affected error rates in older adults, (b) the presentation of an auditory stimulus facilitated responses and decreased reaction times in both younger and older adults, (c) the presentation of an auditory stimulus also increased error rates in older adults, and (d) the effect of response type on error rate remained in experiments conducted under different conditions in older adults. This suggests that in older adults, movement and the associated nervous excitation have significant effects on motor inhibition.