Room monitor, esp. baby monitor or burglar alarm

The monitor (R) is equipped with a stationary telephone (ST) in the room or space being monitored. The telephone is of standard make and has a memory (Sp) for several numbers, loudspeaker and microphone (M1)). The microphone is connected by a line of any length (1) with the telephone and there may be several such microphones (M1,M2,M3,M4,M5) in different rooms connected by the lines (1,2). When there is unusual noise in the room (from a baby or burglar), the microphone (M1) gives a signal to the stationary telephone that dials a number, connecting an external telephone and possibly a mobile 'phone (M0) through the line (3), so that the noise affecting all the microphones can be heard.