2007 Volume 28 Issue 2 Pages 115-123
In this paper, we propose a new adaptive microphone system characterized by a linear prediction circuit inserted before a noise reconstruction filter corresponding to the adaptive delay used in conventional systems. The insertion of the circuit provides various advantages to the adaptive microphone system. One is that steering a null for a noise source becomes possible in spite of an incident speech signal, although conventional systems require the stopping of the null steering during this incidence. Another advantage is that the new microphone system works as an omnidirectional microphone for the speech signal. Consequently, setting the microphones at arbitrary intervals is allowed. For example, building a microphone in a handset and another one in a telephone baseset is possible; thereby, a higher noise reduction effect is expected. We also verify the performance of the proposed system using an experimental system.
