The paper they reference[1] is a paper that describes an approach to formalize human perception of loudness. This is distinct from the sound pressure due to the

The paper they reference[1] is a paper that describes an approach to formalize human perception of loudness. This is distinct from the sound pressure due to the construction of the human auditory system. Here's the relevant excerpt, but you'd have to read the paper to see why they claim this as accurate. > The perceived magnitude (loudness or noisiness) grows as the 2/3 power of the sound pressure, so that perceived magnitude doubles with each increase of 9 dB. [1] Stevens, S. S. (1972). “ Perceived level of noise by Mark VII and decibels (E),” J. Acoust. Soc. Am. 51(2B), 575–601.https://doi.org/10.1121/1.1912880 https://doi.org/10.1121/1.1912880 Available in full from sci-hub