The ITU-T standard defining the Perceptual Evaluation of Speech Quality (PESQ) method of objectively evaluating transmission quality. A companion to the more subjective P.800, PESQ is an automated method that addresses the effects of filters, jitter, and coding distortions. PESQ replaced the Perceptual Speech Quality Measurement (PSQM) method, which was viewed as limited in certain applications. PESQ is considered to be an intrusive test method as it inserts a reference signal into the device under test. See also ITU-T, P.800, PSQM, and toll quality.