Properly made molded plugs block out almost everything. Improperly made molded plugs let some sound past the seal. I prefer the properly made molded plugs to any alternative. Foam plugs are junk as are the little rubber plugs. Hearing range commands is the problem of the range officer. "Speak up, I can't hear you". I am not a fan of electronic plugs. I use muffs over plugs on the rifle range, but plugs only on the shotgun range.