I had a broken eardrum and the ENT doctor used a patch to help the eardrum heal. The patch was changed every week or so, and after each change the doctor had me sit for up to 20 minutes with a large, round, plastic dish next to my ear. I was told this was to promote healing of my eardrum, but I cannot figure out what it could've been. It was a large machine, and I recall a rhythmic ticking noise as it worked. I'm not sure if this was some sort of ultrasound, or infra sound?