Correlation analysis of the speech multiscale product for the open quotient estimation

Abstract

This article proposes a multiscale product (MP)-based method for estimating the open quotient (OQ) from the speech waveform. The MP is operated by calculating the wavelet transform coefficients of the speech signal at three scales and then multiplying them. The resulting MP signal presents negative peaks informing about the glottis closure, and positive ones informing about the glottis opening. Taking into account the shape of the speech MP close to the derivative of electroglottographic (EGG) signal, we proceed to a correlation analysis for the fundamental frequency and OQ measurement. The approach validation is done on voiced parts of the Keele University database by calculating the absolute and relative errors between the OQ estimated from the speech and the corresponding EGG signals. When considering the mean OQ over each voiced segments, results of our test show that OQ is estimated within an absolute error from 0.04 to 0.1 and a relative error from 8 to 21% for all the speakers. The approach is not so performant when the evaluation concerns the OQ frame-by-frame measurements. The absolute error reaches 0.12 and the relative error 30%.