1. What is a Hearing Aid?
  2. How a Hearing Aid is Selected?
  3. Hearing Aid Styles
  4. Some Important Points About Hearing Aids
  5. Can You Hear This?
What is a Hearing Aid?

A hearing aid takes in the surrounding sounds and makes them louder. It is usually in the form of a small plastic covered electronic device that sits in or behind the ear.

Hearing Aid Electronics

Hearing aids are made up of :
  1. A microphone, which picks up the sound and converts in into an electrical signal;
  2. An amplifier which increases the size of the electrical signal; and
  3. An earphone which converts the increased electrical signal back into sound.

How a Hearing Aid is Selected

Every hearing aid should be electronically tailored to suit the person's particular hearing loss. Recent improvements in hearing aid technology have meant that a very wide range of hearing losses can be successfully fitted.

Hearing aids should only be provided after a careful selection process which must include a full hearing test, and an assessment of the person's ability to follow a conversation.

The audiologist prescribes the hearing aid to ensure that it provides the wearer with an even balance of all the sounds of everyday life.

A properly fitted hearing aid will be evaluated and “fine-turned” over a period of time to meet the individual's needs.

Hearing Aid Styles

Hearing aids come in a range of shapes and sizes. The most common ones are:

Open Fit Behind-the-EarBehind the Ear

This is a new style of behind-the-ear hearing device made possible by advances in technology.

Originally designed for the “baby boomers”, it has now flowed into widespread clinical practise throughout the world.

The primary advantage is that the ear canal is unoccluded. This means that one's own voice sounds natural and environmental sounds can be also heard in their unamplified state via the openness of the ear canal.

Sounds are channelled into the ear canal via a near invisible capillary tube that is attached to a mainiature behind the ear device.

The BTE component is generally about the size of the last joint of our little finger rendering it extremely light weight and inconspicuous.

The open fit BTE system is well suited for mild to moderate high frequency loss.

Behind-the-Ear (BTE)

This style of aid sits behind the ear and is attached via tubing to a custom made mould that fits in the ear canal.

Today's behind-the-ear instruments are highly regarded due to their reliability, long life and suitablility for a wide range of hearing loss.

Their unique earmould system reduces “whistling”, making them comfortable to wear.

In-the-Ear (ITE)

This style of aid sits fully inside the ear and is the largest of the in-the-ear models. It is a useful style for patients with limited manipulation ability (such as severe arthritis) as it holds a larger battery and can have larger controls.

It is capable of producing more power suitable for patients with moderate to severe losses.

In-the-Canal (ITC)

A popular style that balances cosmetic appeal, features and functionality.

Receiver in the Ear (RITE)

This is a new technology being introduced by a number of manufacturers. This replaces the conducting sound tube with an electrical wire that drives a miniature loundspeaker, located at its end, in the ear canal.

As there is no conducting sound tube then a smoother acoustic response can be obtained.

This technology does require sophisticated and fast acting feedback cancelling systems to be designed into the instrument to provide acoustic stability.

CROS Hearing Aids

CROS Hearing Aids can be helpful for people with poor hearing in one ear. They consist of a microphone worn on the poorer hearing ear which picks up sound and feeds it to a hearing aid worn on the better hearing ear.

Some Important Points About Hearing Aids

  • 1.  Despite the different styles of hearing aids, they all perform the same basic function, that is, to amplify the sound around us. Each style of aid has its owm particular benefits and limitations in terms of easy manipulation, amount of power, cosmetic appearance and suitability for the wearer.

    There are further choices available to the audiologist in terms of circuitry to suit different types of hearing loss.
  • 2.  As well as matching your hearing loss, a hearing aid should also match your lifestyle. For instance, if you attend meetings in halls, theatres or cinemas that have an audio loop, then telecoil or 'T' switch needs to be built into the hearing aid to take advantage of the audio loop.

  • 3.  If you have any questions about your hearing or your hearing aid, always feel free to ask your audiologist.

Can You Hear This?