Originally Posted by hbillsmith
I read somewhere that db measurements are not linear. Basically, the author said that 1db of measured noise was roughly twice as noisy. Sounded funky to me that 59db would be twice as noisy as 58db. I've had enough experience to recognize that 75db is subjectively a heck of alot louder than 58db, just don't know what multiplier I would use.
Decibels are on a log scale. A 3db increase is double the noise level. 62db is indeed twice as loud as 59db. However, your ears and hearing are not linear, either. Most people have trouble detecting a difference of less than 3db.
That said, there are scales that show how most folks perceive various sound levels. Conversation gets difficult above 70db ambient noise, hearing gets damaged above 108db (IIRC). Whispering is around 52db.