Noise suppression methods for speech applications

This paper presents a discussion and evaluation of several filtering techniques for suppressing narrowband background noise in speech signals. The methods discussed are a modified spectral subtraction technique, an inverse transform filter, an adoptive notch placement technique, an adaptive predictor, and a modification of the adaptive predictor. Performance of the filter methods are compared using a spectral error measurement and an area ratio parameter error measurement. Although the modified adaptive predictor provided the best improvement in spectral error, results indicate the modified spectral subtraction method to be the most suitable for use with linear predictive coding systems.