For me I describe it more as trying to open your jaw with the muscles near your ear, while holding the jaw in place with the main jaw muscles. Like an isometric

For me I describe it more as trying to open your jaw with the muscles near your ear, while holding the jaw in place with the main jaw muscles. Like an isometric hold. I actually didn't know I could do it until now, I could always get the click and it's how I clear ear popping sensations but I didn't realize it I push it harder I get the hollow voice thing and apparently it's useful for diving. Cool.