When I was a lad, I spent some time in front of a mirror trying to teach myself to move my eyebrows independently, like Spock. I eventually succeeded, but in the process I also learned how to move my ears. One downside is that these ear muscles began to involuntarily try to help. For instance, if I am looking down while wearing glasses, my ears contract to grip the glasses so they don't fall off, and after a while these seldom used muscles ache from the effort.