According to a story in the Washington Post, a study from Australia’s National Acoustic Laboratories compared sound levels in fitness classes from 2009 to 2011 with those from 1997 to 1998, and found they were getting ever higher, sometimes as high as 99 decibels.
Adults can safely handle 85 decibels for up to eight hours, and 94 decibels for one hour, according to Deanna Meinke, professor of audiology at the University of Northern Colorado and co-director of Dangerous Decibels, a health campaign fighting noise-induced hearing loss. (Normal conversation is 65 decibels.)
Meinke would like to see sound levels in fitness classes drop to 85 decibels. In the meantime, if you feel like the music in your fitness class is blowing out your eardrums, wear earplugs.