Telephone Hybrids convert an incoming call into an Audio signal for the studio environment. The line echoes on analogue telephone interfaces which result from the 2-wire technology used are disturbing and must be eliminated by line echo cancellers.

Audio Codecs are used for Audio transmissions over different networks like ISDN (dial-up connections and leased lines), LAN, 2-Mbit/s (E1) and X.21. Dial-up connections are used for temporary connections for reporting applications but also for studio programme contribution.

The digital broadcast technology DAB (Digital Audio Broadcasting) is a broadband system, with which several programmes (Audio and data services) can be transmitted from one or more programme providers in one Ensemble.