Apparatus and method for transmitting or replaying multi-channel audio signal

The present invention relates to a device and method for transmitting or playing the multi-channel audio signals, while having a conventional stereo audio based on the system to be backward compatible with efficient transmission of multichannel audio signals. To this end, the transfer unit of the present invention and the multi-channel audio signal, the input receiving a multi-channel transform to the downmix audio signal and additional signals audio down mixing unit, combining the additional signals of said plurality of frames generates additional signals of one superframe which includes a super frame generating unit, and a packetizer for packetizing the addition signal of the superframe.