Quality Control
To make sure that no errors happen during the encoding of audio data, quality control based on psychoacoustic models comes up. This type of check is modeled after the human hearing system and determines differences between coded and uncoded material.
Using psychoacoustic models, two files with the same audio data can be compared - for example encoded with different codecs or bitrates. It also can compare two versions of the same analog material ingested on different tape machines, displaying differences in runtime, in frequency response or spectrum.