The Wavelet Denoising Method with Improved Threshold Function of Respiratory Sound

The novel wavelet denoising method with improved threshold function of respiratory sound is proposed in this paper. The waveforms of different wavelet functions in the time-domain and frequency-domain are compared and the Daubechies wavelet is used for wavelet denoising. The continuity and smoothness of the threshold function are respectively improved by optimizing the parameters of the function. The noise in the signals with complex components is reduced and the cleaner breath sound signal is obtained through the wavelet denoising method with improved threshold function.