psycho-acoustic coding methods use the characteristics of the human ear and remove signal sections that have no effect on the auditory perception before transmission. to develop test methods, a large number of recorded audio samples with various speech and music examples were used. these recordings were then compressed using a variety of coders – and thus different quality levels – and degraded by introducing typical transmission interferences.
a large number of test listeners rated these samples in a series of acoustic tests based on the standard scale for audio quality ranging from 1 (poor) to 5 (excellent). the development of pesq for speech signals and peaq for broadband audio signals provides methods that compare the original undegraded signals (reference signals) with the degraded signals (measurement signals) and then output objective measured values that correlate very well with the average of the listening test results. the r&s®upv offers these measurements in line with the methods licensed by the opticom gmbh company in erlangen, germany.
the measurement method referred to as the perceptual evaluation of audio quality (peaq) was published in 1998 as recommendation itu-r bs.1387 by the international telecommunication union. it is used to measure the quality of broadband audio signals (e.g. music) that are transmitted at a low bit rate using high-compression psychoacoustic coding methods.