If you want to know how loud something seems to a person, use sones. If you want to know the physical sound pressure (for engineering or hearing safety), use dB.
A sound judged to be twice as loud is 2 sones. A sound half as loud is 0.5 sones. This makes sones intuitive for product design and consumer comparisons. sones to db
One sone is defined as the loudness of a 1 kHz tone at 40 dB SPL (sound pressure level). If you want to know how loud something
| Sones | Approx. dB SPL (at 1 kHz) | Perceived Loudness | |-------|----------------------------|--------------------| | 0.5 | ~35 dB | Very quiet | | 1.0 | 40 dB | Reference | | 2.0 | ~50 dB | Twice as loud as 1 sone | | 4.0 | ~60 dB | Twice as loud as 2 sones | | 8.0 | ~70 dB | Twice as loud as 4 sones | | 16.0 | ~80 dB | Very loud (vacuum cleaner) | A sound half as loud is 0