Wikipedia
PESQ
PESQ, Perceptual Evaluation of Speech Quality, is a family of standards comprising a test methodology for automated assessment of the speech quality as experienced by a user of a telephony system. It is standardised as ITU-T recommendation P.862 (02/01). Today, PESQ is a worldwide applied industry standard for objective voice quality testing used by phone manufacturers, network equipment vendors and telecom operators. Its usage requires a license.