I've always been told that I am a great slapper! I know how to make a connection, like hard, with whatever I am slapping. But I have never slapped, My own armpits. They are slightly hairy right now, so I'm thinking the sound might be a different. I start to slap, one armpit at a time and the reaction is instant! My pain faces show how much it hurts when I hit My own pit. I didn't realize how sensitive they were. But I don't give up, I continue to slap repetitively! And hard!