I have 25 decibels and they're pretty good. A little bit if background noise always relieves some pressure anyway. My worst performances have always been in silent back-rooms like multi at Harvard Spring 2012 and 4BLD at SJC.
How db works :
say for example your home noise level is 40 db, and your earmuffs have 25db reduction. That means your house hold noise level will now be 15db to your ears. (40 is about average for a home, and around 110~ are airplanes iirc)
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