Can Noise Counseling Earphones Really Protect Your Ears?

Our ears work by having a membrane and then there's a pressure wave that runs against that membrane. So with the listening to the wave you've got it going up and down. And what happens in your sound cancelling headphones is they listen to the sound coming in and then generates with a little amplifier and upside down wave. The whole system is designed so that when it lands on your eardrum the hill and the valley run into each other and there is no pressure onyour eardrum. There is no pressure and therefore you're not getting any movement of the eardrum and you are being protected. Now for various reasons some earphones work better at the lower frequencies or they work