Hearing aids are electronic device that is worn on/in the ear to help hearing-impaired individuals listen and communicate in everyday conversations. There are many hearing aid manufacturers out there, some of which include: Phonak, Unitron, Starkey, GN Resound, Widex, Signia, Oticon, Sonic and Bernafon. All hearing aids come in a variety of styles and technology levels. Choosing a hearing aid style is dependent on a number of factors including the degree and type of hearing loss, aesthetics, and patient preference. Choosing a technology level is dependent on a patient’s communication needs, lifestyle and budget.
Hearing aids consist of 3 parts: a microphone, amplifier and speaker. The external microphone is able to pick up sounds and convert these sounds into a digital signal. The amplifier within the hearing aids is able to strengthen the signal and the speaker transmits these sounds to the ear. Sounds are then converted from a digital signal to a neural signal that is passed along the hearing nerve and to the brain.
As previously mentioned, there are a number of different styles of hearing aids. This means the shape, size and positioning of the hearing aid are different.
Receiver in the canal (RIC): Most of the electronics are housed behind the pinna with an electrical wire that is positioned down the front of the ear. At the end of this wire will sit a custom tip or dome that is positioned inside the ear canal.
Behind the ear (BTE): All of the hearing aid electronics sit behind the pinna. A clear plastic tube will then run down the front of the ear and will usually have a custom tip or dome at the end of the acoustical tube which sits inside the ear canal.
Invisible in the canal (IIC)/Completely in the canal (CIC): These styles of hearing aids require an impression of the ear, as they are custom made to the individual ear canal shape and size. These hearing aids are discrete and sit deeper in the ear canal compared to any other hearing aid style. These devices are usually recommended if someone is concerned about the look of the hearing aid. This style can come with some limitations in regard to Bluetooth connectivity given the small housing size and are also not suitable for those with more severe hearing losses.
In the canal (ITC)/In the ear (ITE): These hearing aids are custom made that fit into the ear canal with a small section of the hearing aid visible when looking at the outer ear.
An ear impression is a replica of the ear shape/structures by injecting impression material into the ear canal and external ear. Here at Gippsland Audiology, we are highly trained in making safe and accurate impressions use for custom hearing aids and moulds.
Your audiologist will thoroughly assess the health of your ear canal to ensure there is no wax or foreign bodies obscuring the ear canal/view of the tympanic membrane (eardrum). Wax will be removed prior to taking an impression as it is important to have a clean and healthy ear canal before taking an ear impression.
A cotton block attached to a string will be gently inserted into the ear canal. This is positioned quite deep in the ear canal to ensure the ear impression is taken accurately. The cotton is designed to create a barrier and protect the eardrum.
Your audiologist will then combine some ear impression material together and place it into a syringe. The tip of the syringe is then placed into the ear canal and impression material fills the ear. This may feel a bit odd but there should be no pain experienced. It is common to feel like your ear is blocked! The impression material only takes a few minutes to set. Once set, your audiologist will gently and safely remove the ear impression material from the ear canal. The cotton block is also removed, leaving your ear canal clear of any impression material. You will be able to see what your ear shape looks like inside!
Ear impressions are then packed up and sent to a hearing aid manufacturer, so they are able to 3D scan the impression into their software and design a custom hearing or mould solely dependent on the shape and structure of your ear canal and external ear.