Definition - What does Signal Noise mean?
Signal noises are used in workplaces to alert workers to hazards or emergency situations. Since workplaces generally have a high level of background noise, signal noise must be such that it can easily be distinguished above other background noises, or they will not be heard.
Safeopedia explains Signal Noise
Signal noise to workplace noise ratio indicates whether signals will be audible above background noise levels allowing workers to be alerted to potential hazards, such as vehicles with obstructed rear visibility or earth-moving equipment. However, this ratio is also applicable to other hazard and evacuation alarms. OSHA specifies that signal noises should be clearly audible to workers on or approaching a site where such hazards exist.