Arrording to many scientists the universe started with a "big bang" that was so loud that that the noise of it is still reverberating arount the universe. I have heard that the only reason we don't hear this sound is that we are so accustomed to it (as we were hearing it from the moment we were conceived ).

This I don't understand.

The scientists say that even after all this time the "bang" is still incredably loud. As sound travels in waves, the waves from the bang should still be all around us. The human ear works by channeling sound waves into the ear which cause the tempanic membrane (the ear drum) to vibrate which in turn transfers a message to the brain. So why doesn't the ear drum vibrate constantly, (which it doesn't), because of these waves.

If our ear drums automatically cancels these waves so that we can't hear them I wonder what other sounds are out there that are automatically canceled out.