To obtain the small sized inexpensive image and sound signal compander by reducing number of data buses connecting ICs each formed by mounting components on a printed circuit board.

Components 42, 43, 44, 47, 48, 49, 51, 52 similar to each other in terms of circuits and functions in the compression coding and decoding expansion systems are integrated with a changeover switch. In the case of switching the recording and reproduction, the switch is open/close by a switching signal generated from a recording and reproducing changeover signal generating means 54 when the recording or the reproduction is selected to connect only one system of components corresponding to each IC to data buses 55 interconnecting the ICs.