PSQM

PSQM (Perceptual Speech Quality Measure) is a computational and modeling algorithm defined in ITU Recommendation ITU-T P.861 that objectively evaluates and quantifies voice quality of voice-band (300 – 3400 Hz) speech codecs.It may be used to rank the performance of these speech codecs with differing speech input levels, talkers, bit rates and transcodings. The ITU-T has Withdrawn P.861 and replaced it with P.862 (PESQ) which contains an improved speech assessment algorithm. PSQM (Perceptual Speech Quality Measure) is a computational and modeling algorithm defined in ITU Recommendation ITU-T P.861 that objectively evaluates and quantifies voice quality of voice-band (300 – 3400 Hz) speech codecs.It may be used to rank the performance of these speech codecs with differing speech input levels, talkers, bit rates and transcodings. The ITU-T has Withdrawn P.861 and replaced it with P.862 (PESQ) which contains an improved speech assessment algorithm. Using the PSQM standard allows automated, simulation-based test methodologies to objectively rate both speech clarity and transmitted voice quality. Various software and/or hardware products have been developed to facilitate this testing. This results in considerable savings in cost and time over the traditional practice of using large groups of people to subjectively evaluate voice signals and assess voice quality. Moreover, it yields objective results that are reliable and reproducible. This is very important to telephony providers who are mandated to maintain high Quality of Service standards. PSQM uses a psychoacoustical mathematical modeling (both perceptual and cognitive) algorithm to analyze the pre and post transmitted voice signals, yielding a PSQM value which is a measure of signal quality degradation and ranges from 0 (no degradation) to 6.5 (highest degradation). In turn, this result may be translated into a Mean Opinion Score (MOS), which is an accepted measure of the perceived quality of received media on a numeric scale ranging from 1 to 5. A value of 1 indicates unacceptable, poor quality voice while a value of 5 indicates high voice quality with no perceptible issues.