Jeff,

Yes, some, if you know when the weapon is going to be fired, or you are the one pulling the lanyard, you open your jaw to protect your eardrums, it helps some. A number of times deafening blasts stayed wth me for days, Old Macrobe put out a burst from a thompson right next to my left ear one night, that ear whistles and rings from time to time.

__________________
All the Best
Jack