Telephony with usual telephone sets is very difficult or associated with great effort in a noisy environment. Previously obtainable supplementary devices are subject to licences and fees and cannot be used immediately, either. The invention provides a remedy by means of a headset which provides for undisturbed telephony without electrical connection. It comprises a headset which is worn by the person who is telephoning, and an acoustic or magnetoacoustic coupler onto which the telephone receiver is placed for conducting a conversation. The headset and the acoustic coupler are connected via signal lines, amplifiers and possibly band pass filters being arranged in these lines. Switching-on and -off is done via a switch which is operated by the telephone receiver.
