Microphone array placement has an important influence on the performance of microphone array speech processing system.For the performance of its time delay estimation(TDE)
Cramér-Rao Bound(CRB)of TDE is derived by use of geometrical description of source and microphones
and the effect of microphone array configurations on its TDE performance is analyzed in this paper.Simulation experiments are done on the TDE performance of conventional microphone array configurations.Simulation results effectively verify the conclusion.