Improvements to the HNR estimation based-on generalized variogram

Abstract

The presence of an unusual high level of turbulent noise in voice signals is related to air leakage in the glottis as a result of incomplete closure of the vocal cords. Harmonics to Noise Ratio (HNR) is an acoustic measure that intends to appraise the amount of that turbulent noise. Several algorithms have been proposed in both time and frequency domain to estimate HNR. The Generalized Variogram (GV) is a time-domain technique proposed for HNR estimation based on a similitude function between two speech windows. The drawbacks of the GV are related to the biased estimation of the amplitude ratio and the final HNR value. The present work deals with these limitations and proposes unbiased estimators. The experimental results show that the described improvements outperform the original GV. © Springer-Verlag 2013.