Evaluation of dual channel adaptive noise canceller for speech enhancement

A dual channel system for speech enhancement is proposed and evaluated under babbling noise. A two stage dual channel structure of adaptive filters is used with different microphones, one directional for receiving the desired signal and the other omni directional for receiving the ambient noise which for this model is mainly babbling. Simple Root Mean Square (RMS), Itakura-Saito Distance (ISD) and subjective evaluation tests are made in order to ease comparisons against single stage adaptive filter. Using a simple adaptive filter, it is not enough to reduce background noise while maintaining the intelligibility of enhanced speech. Therefore, a noise emphasizing channel is used in order to achieve a better noise canceling. This work is done as precedent for the implementation of a system capable of diminish the noise from voices different than the target by using adaptive filter structures offering good results but small enough to be embedded in hearing aid devices.