Figure 2: The three models of hearing protectors tested in this fi eld study. The 3M™ Combat Arms™ Single Tip earplug has a toggle that was opened during testing. The Etymōtic Research ETYPlugs® Earplug was tested as is. The 3M™ Peltor™ TacticalPro Communications Headset was tested with electronics on and set to unity gain. The double protector combination of the ETYPlugs earplug and TacticalPro earmuff was also tested