Effects of intense continuous- and impact-type noise on pupil size and visual acuity.

The data obtained from these studies suggest that continuous noise at high levels will produce an increase in arousal, as indicated by pupil size, and that there is a tendency toward adaptation. At lower noise levels the effect is, at most, transitory. This papillary change does not appear to mediate a change in visual acuity. Impact noise such as that used here does not appear to produce reproducible changes in pupil size or visual acuity. For the noise conditions used here, concern for nonauditory sensory effects seems to be unwarranted.