Master's Thesis from the year 2016 in the subject Electrotechnology, grade: P5, Edinburgh Napier University, course: M.Sc in Electronics and Electricals - Digital signal processing, language: English, abstract: Audio signals are more frequently polluted with various types of realistic noises. So, periods ago in order to reduce the noise level, some filtering approach will be used. But, presently there are many transform based techniques to estimate the noisy audio signal. One of the transform technique known as wavelet transform will be used for denoising an audio signal from realistic noise. Predominantly, the objective of this proposed research is to characterise discrete wavelet transform (DWT) towards denoising a one dimensional audio signal from common realistic noise. Moreover, the idea is to implement the audio signal denoising techniques such as decomposition, thresholding (soft) and reconstruction in the MATLAB simulation software, and elaborate a comparative analysis based on choice of wavelet transform over Fourier transform. Likewise, for the different level of decomposition, signal to noise (SNR) will be estimated .To sum up, in this research, different circumstances has been measured to elect best wavelet function and its level, based on its response of signal to noise ratio (SNR) in denoising audio signal.