Supplementary to Audible Alarms: VADs are specifically effective in significant-noise areas or wherever hearing security is worn, supplementing conventional audible alarms. Tasks drop into the next types: online video; photography; art; interior design and style and architectural scientific tests; textile and clothing administration; strategic communications and graphic structure; the... https://www.firesense.co.uk/type/addressable-fire-system/addressable-sounders-vids-vads/