“…4 5 , 4 6 After reviewing a substantial amount of the pertinent literature, one is forced to co.,clude that the proper and faithful use of an ear defender in a traumatically noisy environment, or where a real hazard of blast injury exists, is wise and worthwhile. 32, 34,40,47 The placement of gun crew members should certainly be made with the threat of muzzle blast in mind. Wherever the muzzle blast overpressure approaches 4 psi, the crew members should be protected by ear defenders.…”