What is a Sone Rating?
If you’ve been looking to buy a bathroom fan, kitchen range hood or other home appliance equipped with an exhaust fan, you may have noticed most products are given a sone rating. For those who are sensitive to background noises, understanding sone ratings is especially helpful when you’re looking to buy a fan-equipped product with a low noise level.
So what is a sone rating? A sone is a linear measurement of loudness based on how an average listener senses sound. It is different than decibels and volume, which are most commonly used to measure the intensity of audio. Instead, sones are measured by speed, or maximum cubic feet per minute.
For instance, a bathroom fan with a sone rating of 0.3 is considered to be very quiet. If another bathroom fan had a sone rating of 0.6, its sound level would be twice as noisy as the aforementioned fan. For comparison, a quiet refrigerator usually has a sone rating of 1.0, while a quiet indoor space (like your house) might register at a 2.0 sones. A television at a normal room volume would come in at about 4.0 sones.
If you’re in the market for a relatively quiet bathroom fan, look for models with a sone rating of 1.5 or under. In general, there is no good or bad sone rating, as a tolerable noise level usually depends on your personal preference and your noise sensitivity.
For those who are looking to compare the sone rating for kitchen range hoods, keep in mind the sones will be higher if the cubic feet per minute (CFM) rating is also higher. CFM measures the amount of air movement generated by a fan; the more air a range hood circulates, the more noise it will make. Most range hoods are available with sone ratings of 2.0 and up to 7.5.