Fire alarm sounders should be installed throughout the building with an even distribution, to generally provide a minimum sound level of 65dB(A) or 5dB(A) above any background noise which is likely to persist for more than 30 seconds.
Where the alarm may have to arouse sleeping persons e.g. hotel bedrooms, nursing homes, etc, a minimum sound level of 75dB(A) is required, at the bed head with all the doors shut.
All fire alarm sounders in a building should produce the same sound, distinct from any other audible warning devices in the building.
Where fire alarm sounders are required in extremely noisy areas e.g. machine shops, it may be necessary to install additional fire alarm flashers.
