I have personally had an eardrum broken while wearing the WEKAF style masks. The cups that are supposed to protect your ears can actually catch air on a direct hit and the shock wave is what broke the eardrum. To compound matters, my opponent was swinging a homemade padded stick which consisted of a 7/8" stick with pipe insulation on it. The added mass and diameter from the insulation didn't help. I personally feel much safer in a well built fencing mask (and not using such padded weapons, Actionflex is good, though).
Dog Chuck