Types of Hearing Aids
The Behind-the-ear Aid
The components are housed in a case behind the ear and linked to the ear by a tube and ear-mould.
This is by far the most commonly prescribed aid under the National Health Service. With well-fitting ear moulds, acoustic feedback (whistling) is minimal even if two powerful aids are needed to correct a profound hearing loss.
This aid can be uncomfortable for people wearing glasses and troublesome for active people in outdoor pursuits.
Range and performance of The Behind-the-ear Aid
These are the most common hearing aids on the market. They are the largest type of hearing aid and the microphones are kept out of the ear although feedback (squealing or whistling) can still occur, but usually at a much higher amplification level than In-the-ear models because of the speaker/microphone positioning.
Their size permits complex circuitry with numerous options.
For mild to profound hearing loss, powerful and reliable.
This aid is a must for profound hearing loss (power needs) and for small children since only the ear mould needs to be replaced as the ear size changes, and not the whole aid.
More visible (although with normal hair length they are often covered).
Loss of natural ear resonance with the microphone outside of the ear, but the frequency response of the amplifier and tubing help restore as
much as possible. Wind noise and other sounds such as rubbing coat collars and hats can be distractive. Hearing aid (microphone especially) is more at risk for water damage
The In-the ear hearing Aid
The components are housed in a case which fits in the ear so there is no link to the ear by a tube.
These come in various sizes, the smaller models have carefully chosen circuits from thousands of variations to give the best performance to compensate the patient’s hearing loss.
They are quite robust for an active wearer.
Range and performance of the In-the-ear Aid (ITE)
They are still the most popular style of aids sold today although smaller sizes have been available for more than 15 years.
Greater flexibility in the number of adjustable parameters (for conventional circuitry), room for a longer battery life, larger volume control for ease of manipulation, easier to insert and remove, traditionally more maintenance free.
For mild to severe hearing loss.
Ideal for all degrees of hearing loss except profound, and/or for those with dexterity concerns.
Most visible of all In-the-ear styles, increased chance of wind noise and some loss of natural sound quality (although the last two can be corrected somewhat with proper fitting).
Recommended for mild to moderate flat or high frequency losses.
The Completely in the Canal (CIC) hearing aid
The closer the hearing aid and the receiver is to the ear-drum the more efficient is the hearing aid.
Consequently the family of hearing aids which fit entirely in the ear canal are called Completely in the Canal hearing aids.
They are the result of advances in micro-technology. Their popularity is that they are comparatively unseen compared to the Behind-the-ear hearing aid.
Range and performance of the Completely in the Canal Aid (CIC)
They are the latest advances in size reduction. Manufacturers can put higher powered and more sophisticated circuits inside a smaller package.
These models sit entirely into the ear canal and are rarely visible to the casual viewer. They are pulled out of the ear by use of an extraction filament.
Advantages include an even greater use of ear canal resonance for more high frequency amplification, less power needed for similar hearing losses fit with other models due to the proximity of the speaker to the eardrum, and a theoretical reduction in what is called the occlusion effect which is perceived by the user as a hollowness in the sound quality. This last point is often not realised in clinical use since the CIC is often rounded and made smaller for comfort purposes.
Recommended for mild to moderate flat or high frequency losses although greater losses have been fitted successfully.
Their popularity is that they are comparatively unseen compared to the Behind-the-ear hearing aid.
Circuit selection, power requirements, option selections and battery life are all greatly reduced. Additionally, not all individuals are candidates for CIC’s due to size and shape of the ear canal.
Spectacle Hearing aids
These aids are considered mainly suitable for men because the hearing aid is housed within the frames of the glasses, which are therefore very thick and supposedly masculine looking. (see diagrams right)
All aids outlined previously are generally termed air-induction hearing aids because the sound from the aid is passed into air and to the ear-drum.
Most spectacle hearing aids are bone induction aids. The sound is passed from the hearing aid through the hook of the pair of glasses and into the mastoid bone. This is the bone which is behind the ear and close to the surface.
The sound passes from the ear through the mastoid bone and into the inner ear. This means the process is not affected by any deficiencies in the middle ear. Some patients, who feel uncomfortable with an ear-mould or just physically cannot have anything in their ear use spectacle hearing aids.
Some patients just prefer the look of the spectacle hearing aid.
Viennatone cover the main market for spectacle hearing aids. Use Contact us if you want to see them.
Suitability and Ear moulds
It must be remembered that the choice of hearing aid does not always depend on the patient’s preferences but also which type of hearing aid is suitable for that patient’s hearing loss.
The ear mould or shell i.e. the moulded piece of plastic which houses the hearing aid system, is of tantamount importance.
Every ear is a different shape so each mould has to fit properly otherwise feedback occurs. This will be decided after a discussion with your dispenser.