The Eardoc is a simple resonating device designed to shake open the Eustachian tube and allow any liquid inside to flow out. Below is a short video by the manufacturer showing how the system works.
Product page: Eardoc
Eardoc Offers Drug-free, Noninvasive Ear Pain Relief (Supposedly)
February 12th, 2008 
Medgadget Editors ENT, Pediatrics
Product page: Eardoc