The sone scale compares loudness on a linear scale by assigning a value of 1 sone to a loudness of 40 phons, 2 sones to a loudness of 50 phons, 4 sones to 60 phons. This continues to double the number of sones at each 10 phon increase up to a value at the top of the scale of 64 sones, corresponding to a loudness of 100 phons. The sone is a unit defining how loudly a sound is perceived.Continue Reading
A decibel is a measure of sound intensity. The phon is a unit that measures loudness, taking into account the frequency of a sound in addition to the intensity. If a sound is as loud as a 60-decibel sound at a standard frequency of 1000 Hz, it is defined to have a loudness of 60 phons. To determine the loudness of a complex sound, scientists compare it to a 1000-Hz test tone using filter contours to approximate the human ear.
Since the phon is based on the decibel, it is a logarithmic unit. In 1936, Stanley Smith Steven created the sone scale to provide a measurement that was directly proportional to loudness. Orchestral music typically ranges from 40 to 100 phons, so Stevens arbitrarily assigned a value of 1 sone to 40 phons, and 64 sones to 100 phons.Learn more about Measurements