Which of the following is an example of intermittent noise?

The correct answer is gunshot, as it exemplifies intermittent noise due to its sudden, sharp nature and brief occurrence. Intermittent noise is characterized by fluctuating sound levels that are not continuous; rather, they come and go over time. Gunshots are loud sounds that occur in quick bursts and are not sustained, making them a classic example of intermittent noise in workplace and occupational settings.

Engine noise, while it can vary in volume, is usually more constant and relentless throughout its operation, which does not fit the definition of intermittent noise. Hammering a nail can create bursts of sound, but typically the noise is periodic rather than intermittent, as it occurs repeatedly in a somewhat predictable pattern. Continuous humming, on the other hand, represents a consistent and steady sound, which is the opposite of intermittent noise. Thus, gunshots best capture the essence of noise that is irregularly spaced and momentarily present.