US Patent 7886745 Self-fitting device for location in an ear canal

A self-fitting device for location in an ear canal. The device includes a body having a body ear end, an opposite body user end, and a shaft extending from the ear end to the user end. A resilient bladder is joined with the body ear end and a chamber is defined inside the resilient bladder where the chamber is in communication with the shaft and the resilient bladder has a wall portion and is deformable from an at-rest position to an in-ear position. The resilient bladder has a variable strength profile in the wall portion of the bladder.