Talkback systems derive their roots from the public exchange telephone system. In many cases the systems are not dissimilar today with the concept of a central switching unit, or exchange, connecting and routing many incoming and outgoing circuits. In the television production environment different technical
and production areas have their own priorities and so must work in acoustic isolation. The studio floor or recording area must be quiet so all operators require headsets for communications with other areas. All areas must be able to communicate efficiently if the production process is to operate smoothly. Talkback systems have evolved dramatically over the years. Systems which were set up and operated by the sound supervisor or sound engineer have now increased in complexity to the point of requiring at least one communications engineer, and often more, to operate and service the system. A talkback system in a studio or outside broadcast environ-
ment is normally based around a mainframe audio switching matrix which may operate in the analogue or digital domain, where inputs and outputs, sources and destinations, may be selected to provide communication paths between areas. The system is analogous to a telephone exchange with its switched lines between telephone subscribers.