What is a sone? A sone is another one of the wonderful terms the acoustical industry has generated to confuse all of us. Sones are most commonly found in the rating of small fans; even more so for residential bathroom fans. Personally, we would not select a fan that is any louder than 2-1/2 sones for our home, which is a level that is noticeable but not objectionable to most people. To give you an idea about how loud a sone is, 6 sones is the level that we typically speak at when seated around a conference table. Keep in mind that noise is a subjective thing which varies depending on a person's tolerance to such. One person's Metallica is another person's Mozart. The following table relates sones to A-weighted decibels.

As you can see, sounds heard at 80 dB are not merely twice as loud as 40 dB, but are actually 16 times louder!