Is a means of occupying and entertaining users in the whole area or on a specific piece of equipment.
It can be just background sound but usually includes a visual element enabling you to play/show different programmes in different areas at different volumes via TV, radio, CD or MP3 etc. Delivery is either wired or wireless and can be linked to background sound for communal or personal use.
Wired is "exactly what it says on the tin." Individual machines are connected to a distribution point giving the user a choice of channels, any one of which can be linked to TV, radio etc.
Wireless is more flexible and provides three options: