There are three reasons why people experience difficulty with insertion of RIC-style hearing aids:
First, it is too difficult to manipulate and control the receiver as the user attempts to insert it deeply enough in the auditory canal. The receiver’s inadequate, smooth surface area does not accommodate the fingertip so the fingertip slides off and past the receiver.
Second, our patients’ auditory canals are often; angled (sometimes sharply) in one direction or another, include various bends, and obstructed by cartilage.
Third, our patients are often older and may have physical limitations and disabilities (including mobility limitations, tremor and dexterity issues) and, along with all of this, limited patience.
Others have documented the problems. Here are two other Patent Application Publications.