Merv the problem with muffs are getting a 100% seal. Wearing glasses or your hair breaks the seal. Also they never seem to compress evenly around your ear. Not looking to argue, heck I wear muffs myself almost 100% when I do wear ear protection.
Looking at the chart we are both right, depends what frequency. But your more correct!
http://www.audiologyonline.com/artic...article_id=296