Sub-band adaptive filtering applied to speech enhancement

An adaptive noise cancellation scheme for speech processing is proposed. In this, the adaptive filters are implemented in frequency limited sub bands. In previous work, the filters had been distributed in a linear fashion in the frequency domain. This work investigates the effects of spacing the filters more in sympathy with the signal power and spectral characteristics. It emerges that improvements in signal to noise ratio of processed noisy speech signals may be obtained when the sub bands are spaced according to a published cochlear function.