Hearing Protection Act This bill removes silencers from the definition of firearms for purposes of the National Firearms Act. It also treats persons acquiring or possessing a firearm silencer as meeting any registration and licensing requirements of such Act. The Department of Justice must destroy certain records relating to the registration, transfer, or making of a silencer. The bill also revises the definition of firearm silencer and firearm muffler under the federal criminal code and includes such items in the 10% excise tax category.