ISO 7731: Danger signals for public and work areas - Auditory danger signals
Disruptive factors may impair the audibility
In general, when planning acoustic signals, it is assumed that the sound volume of a sounder is the only selection criteria. However, this assumption is not correct: in production facilities, buildings and all other public areas, a variety of factors, such as the frequency of the ambient noise, insulated walls or protective equipment like e.g. ear protectors can impair the perceptibility of acoustic signals.
As a conclusion it is important that an acoustic sound system not only provides loudness but is also able to cover certain frequency ranges when generating sound. It must be ensured that this sound is effectively perceivable by the human ears and clearly distinguishable from the ambient noise.
Download: the requirements of ISO 7731 at a glance
What are the main requirements to an Audible Danger Signal and how to select the right one?