Psychoacoustic quantization is the only stage in audio coding that removes signal information

Evidence

In order to make the reduction of information flow inaudible, it is best to use the characteristics of the human ear as an information receiver, and reduce the information flow for those events that are already inaudible. The effect of masking is a typical example. It can be introduced into the processing system in such a way that those parts masked by loud sounds are not transmitted to the receiver. — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 2020 (#contradicts, via linked claim)

Lossy audio coding systems: These systems make use of similar techniques to that of lossless coding but, in addition, reduce the data further by quantizing the signal to minimize the number of bits per sample. In order to achieve this with the minimum of perceived distortion, some form of psychoacoustic model is applied to control the amount of quantization that a particular part of the signal suffers. Because this type of coding removes, or loses, information from the audio signal, it is known as a “lossy coding system.” Unlike the lossless systems, these coders do not preserve the input signal; the output signal is not identical to the original input. The output signal is thus distorted but hopefully in a way that does not disturb and is inaudible to the listener. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2581 (#qualifies, via linked claim)

Categorization

• XREF: connects to: Psychoacoustics developed in parallel, not from, physiology and was shaped by communication engineering; Psychoacoustic quantization is the sole lossy stage in audio coding. — David Howard, Jamie Angus, coustics and Psychoacoustics, 2582; Psychoacoustic models govern which audio information can be discarded unnoticed (+4 more)

Broader Connections

• Audio compression exploits masking to discard inaudible signal parts #contradicts (0.82) — Professor Dr.-Ing. Hugo Fastl, Professor Dr.-Ing. Eberhard, Psychoacoustics- Facts and Models, 2020
• Lossy coding exploits psychoacoustic models to make removed information inaudible #qualifies (0.75) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2581
• Audio compression maximizes information by encoding only unpredictable signal parts #corroborates (0.72)