I have discovered a stupid trick you can do with your body by dumb experiment. Take a feather duster, or some other suitably tickly artificial alternative, and place it on your face lengthwise, so it runs from your forehead down the length of your nose to your chin. The length of the duster should be in contact with your face. Now slowly roll the duster to one side or the other, keeping parts of it in contact with your face at all times. Yes, it should be tickly, by contrast to the way that your body does not let you effectively tickle yourself, no matter how tickly ticklish you are.
The strange bit comes when the duster reaches a cheekbone. Your ear's natural defence mechanisms will take over and the muscles inside will tighten up, with consequences on what you hear. It should work with both ears. It's quite possible to trigger these muscles voluntarily and sometimes they contract involuntarily, especially when you're expecting to hear a loud noise. However, unless you're thinking about it really hard, this is a way to make them contract.
Try it! I'd love to know whether you find the same or whether I'm being more of an alien than usual. (Perhaps it only works if you're naturally tickly in the first place.)
