In-service nonintrusive measurement of noise and active speech level in telephone-type networks

The paper presents an in-service, nonintrusive technique for the measurement of noise level and active speech level in telecommunication systems. It is based on the segmentation of the signal observed during a telephone call into active speech and noise intervals and on an improved method for level estimation via the determination of the noise-level probability density function. Experimental results show the high accuracy of the method also under poor signal-to-noise ratio conditions and its robustness with respect to other real-life impairments found in telecommunication lines.