A New Lattice LP-Based Post-Filter for Adaptive Noise Cancellers in Mobile and Vehicular Applications

Abstract

Adaptive noise cancellation (ANC) is a well-known technique for background noise reduction in automobile and vehicular environments. The noise fields in automobile and other vehicle interior obey the diffuse noise field model closely. On the other hand, the ANC does not provide sufficient noise reduction in the diffuse noise fields. In this paper, a new multistage post-filter is designed for ANC as a solution to diffuse noise conditions. The designed post-filter is a single channel linear prediction (LP) based speech enhancement system. The LP is performed by an adaptive lattice filter and attempts to extract speech components by using intermediate ANC signals. The post-filter has no processing delay which is suitable for speech communication systems. We have evaluated the performance of proposed system in various real-life noise fields, recorded in an automobile environment. The experimental results using various quality measures show that the proposed method is superior to both the adaptive noise canceller and LP-based speech enhancement systems.