A novel simplified mixing model (SMM) is proposed for audio blind signal separation (ABSS).The SMM uses the fact that the room impulse responses from a single source to two closely spaced (approximately several 10 cms apart from each other) microphones are very similar.Only the difference between these two impulse responses is needed.As a result

the computational complexity of ABSS is reduced to some extent.A real-time blind signal separation DSP experimental system has been designed and implemented based on the SMM.The real-time experimental results have shown that the proposed simplified mixing model is effective and feasible. In particular

the blind signal separation performance can be improved considerably by introducing a time delay to solve the inverse problem of a non-minimum phase transfer function.