Industry testing of voice quality output from mobile devices
Carol Espy-Wilson, Xinhui Zhou, Ali Akrouf · The Journal of the Acoustical Society of America · 2016
In general, the commercial evaluation of speech for telecommunication is focused on what is called “speech quality” rather than intelligibility per se. This talk will discuss the current state-of-the-art in the context of the objective test model 3QUEST (3-fold Quality Evaluation of Speech in Telecommunications) developed by Head Acoustics. 3Quest is an objective evaluation of transmitted speech with background noise and we will discuss the new ETSI standard that it is based on. The particular improvement relative to previous objective methods (PESQ and POLQUA) is that influence of different background noises is taken into account and the calculation of three mean opinion score (MOS) values, one each for the speech-only regions of the signal (SMOS), the noise-only regions of the signal (NMOS), and the total signal (GMOS). These scores allow for a more meaningful statement regarding the causes for the impression of quality. Using examples, we will discuss how signal noise, intelligibility, and quality are interrelated as signals are affected by various parameters.