Different Hearing Aid Types/Styles (Most Popular)...
These may be the most popular but there are many others.
RIC: The receiver-in-the-canal device is small, discreet, and incredibly quick to fit; perfect for many first-time wearers.
RIC AP: Receiver-In-Canal Absolute Power. The receiver-in-canal Absolute Power instrument combines a custom-formed ear mold with the sleek, sophisticated receiver-in-canal instrument allowing people with even the most severe hearing loss to enjoy style without sacrificing power and performance.
CIC: Completely in the Canal. These devices fit completely in the canal. Only the head of a tiny plastic line—with which you insert or remove the instrument—shows above the canal.
ITC: In the Canal. In-The-Canal instruments feature an ear mold that fits down into the ear canal and a smaller portion that faces out into the outer ear.