Alyson Earle, Audiologist with Sackville and Alderney Hearing Centres demonstrates an impression of the ear canal.
Ear canal impressions are required to manufacture custom hearing aids, hearing aid earmolds, hearing aid custom tips, custom hearing protection and sleep plugs as well as in-ear monitors used by musicians.
The ear canal must be free of debris or excessive wax in order to obtain a good impression. The audiologist will confirm this by looking into the ear canal using an otoscope. An otoblock, a small, circular shaped piece of foam, is then placed into the ear canal and the impression material is then inserted. In this video, Alyson is using a cartridge impression gun which mixes a two-part addition silicone impression material. Once the impression material is cured, the audiologist will then break the seal by pulling back on the pinna (the outer ear) and then the impression is extracted by pulling outwards and twisting forward toward the nose of the client. The audiologist will then take a look in the client's ears again. It is not unusual to experience some slight discomfort when having impressions taken, as the ear canal is a very sensitive area.
A good ear canal impression will be deep enough that it is ideally past the second bend of the ear canal and will have no holes or gaps. It is important to obtain a good impression of the ear canal to ensure a proper fit of the hearing aid or custom ear plug that will be manufactured.