1.3.11-17 Signal Intensity

The intensity of auditory signals should be set to unmistakably alert and get a user's attention.

Additional Information:
A signal should generally yield a 20dB signal-to-noise ratio in at least one octave band between 200 and 5000 Hz. This level should apply throughout the main operating area. (A 20dB differential may not be necessary for all signals and all environments.) Auditory signal intensity should not cause discomfort or 'ringing' in the ears. Auditory signal intensities should not exceed 90 dB(A), except for evacuation signals, which may be up to 115 dB(A).