Sone (Paperback)

High Quality Content by WIKIPEDIA articles! The sone was proposed as a unit of perceived loudness by Stanley Smith Stevens in 1936. In acoustics, loudness is the subjective perception of sound pressure. Although defined by Stevens as a unit, it is not one of the SI units. Such units meet the stringent criteria of metrology, which include being realizable in a highly precise and reproducible manner, and so transferable for scientific and industrial purposes in a range of contexts. According to Stevens' definition, the sone is equivalent to 40 phons, which is defined as the loudness level NL of a 1 kHz tone at 40 dB SPL. The number of sones to a phon was chosen so that a doubling of the number of sones sounds to the human ear like a doubling of the loudness, which also corresponds to increasing the sound pressure level by approximately 10 dB, or increasing the mean square sound pressure by a factor 10 (since due to the major property of logarithms for any given sound pressure level