Estimation By Means of Wavelet Analysis of the Signal-to-Noise Ratio of Dysphonic Voices

Abstract

The objective is to explore a procedure for isolating additive noise in vowels, and estimating the signal-to-noise ratio. The method is founded on the wavelet transform, which is a family of multi-resolution analysis methods. The breakdown of sonorants into a noise and a signal constituent relates to the observation that additive noise is mostly high-frequency or low-amplitude. The segregation of the noise is therefore based on the isolation of the wavelets of the highestresolution scale or, alternatively, on those whose amplitude is below a critical threshold. The analysis method was tested on a corpus of [a],[i],[u] vowels sustained by healthy and dysphonic speakers. Results suggest that isolating noise via thresholding is preferable to assigning high-resolution scales to noise and low-resolution scales to the signal. Keywords--- Signal-to-noise ratio, Wavelet Transform. I. Introduction The article is concerned with gauging the amount of noise in vowels in view of the description ..