Supplementary to Audible Alarms: VADs are specifically helpful in higher-sound parts or where by hearing safety is worn, supplementing standard audible alarms. As a way to prevent discrimination, BS EN 54-23 compliant VADs may be mounted in all sanitary accommodation (not simply WCs) and all lodge bedrooms, college student accommodation https://www.firesense.co.uk/type/addressable-fire-system/addressable-sounders-vids-vads/