Phons |
Sones |
Music Dynamics |
---|---|---|
120 | 256 | |
110 | 128 | |
100 | 64 | fff |
90 | 32 | ff |
80 | 16 | f |
70 | 8 | |
60 | 4 | p |
50 | 2 | pp |
40 | 0.5 | ppp |
32 | 0.25 | |
25 | 0.25 | |
19 | 0.125 | |
14 | 0.0625 | |
11 | 0.03125 | |
9 | 0.015625 |
The phon and sone are units of perceived loudness. The phon is proportional to signal intensity in dB, while the sone is linear with perceived sound. Therefore, the two scales are not proportional. According to the definition by Stanley Smith Stevens who proposed the phon as a unit of loudness in 1936, 1 sone is equivalent to the loudness of a signal at 40 phons, which is equivalent to the loudness of a 1 kHz tone at 40 dB SPL.