A Wavelet Based Audio Denoiser

TThis article discusses real-time denoising algorithms for digital audio based on the Wavelet Transform. White noise is located in all frequencies and is thus especially hard to detect. We use the locality of the wavelet function to single out the frequency domains of the signal itself and thereby be able to denoise it. Perfect denoising is not possible: the higher the threshold coefficient is set, the more noise is detected, but the more the original signal is affected as well. We have implemented a flexible framework for denoising that includes hard and soft thresholding, different Wavelet Transforms, and different treatment of the padding coefficients. The presented denoiser is a real-time application that allows direct subjective judgments of a parameter setting. An evaluation will conclude the article