Scale-Invariant Modification of COSH Distance for Measuring Speech Signal Distortions in Real-Time Mode

This study considers a new measure of distortions of speaker speech sounds that is invariant with respect to the gain of speech signal in a communication channel. Properties of the measure are investigated in comparison with its closest analogues. A series of theoretical features has been proved. The new measure is shown to combine advantages of the symmetric Itakura distance in relation to the noise immunity of automatic speech processing, on the one hand, and of the COSH distance in relation to the sensitivity to speech signal distortions, on the other hand. Using the proprietary software, an experiment was set up and conducted. Estimates of the new measure dependence on the signal-to-noise ratio were presented. It has been shown that the logarithmic presentation of this relationship has the pattern close to linear. The obtained results are intended to be used in development of new systems and upgrading of existing systems and technologies for digital signal processing and speech quality analysis under the noise exposure.