Accessibility at NSW CLIC

This page includes technology options associated with hearing aids.

• Hearing aids
• Body Aids
• Behind the Ear Aids
• In the Ear Aids
• In the Canal Aids

Hearing Aids

Description

Four types of hearing aid are discussed below. However, specific examples will not be given. One reason is that, with over 600 models of hearing aids being available in Australia (far more than the number of motor car models), listing several examples would serve no useful purpose. As discussed below, the tailoring of an aid to the individual’s needs is also crucial.

The aid receives sound through a microphone and amplifies it to suit the ear of the user. Regardless of the type of aid, an important component is the ear mould. As the name suggests, the mould (or two if both ears are aided) is shaped to suit the shape of each person’s ear. It is important that the mould fits correctly, partly so it is comfortable but also to prevent sound leakage. In many cases the mould will have a vent, which allows sound to enter the ear normally. As hearing deteriorates and greater power from the aid is required, the vent must be made smaller or completely removed. If this is not done, feedback in the hearing aid will occur, resulting in a high-pitched whistling sound. A discussion of ear moulds alone could occupy far more space than is available on this page, but the topic will not be taken further here.

Historically, hearing aids received and amplified sound through analogue technology. Some current aids process the information digitally. Others, while processing the information with analogue electronics, are adjusted through digital software to suit an individual user. In either case, these advances allow more precise adjustment. Hearing aids now commonly have two or more listening programs. This allows the user to select quickly a program for listening in quiet conditions and a different program for noisy situations.

Importantly, a hearing aid is tailored for each individual on the basis of an audiogram. That is, the aid is tuned to boost the frequency range(s) where the user’s hearing loss is the greatest. The accuracy of this process is critical to the aid’s effectiveness.

Tswitch

Some aids are equipped with a T (telecoil) switch. This allows clear reception of sounds from external amplification via a magnetic-field loop, an induction plate or neckloop. When switched to the T position, most aids do not respond to ambient sounds through the microphone of the aid. The advantages of telecoil are described in Equipment for use with Hearing Aids. Some aids, however, offer a third option, where both sources can be received simultaneously. Another facility provided on some aids is an audio input for such options as induction plates, neckloops, audio input and magnetic-field loops.

A hearing aid may be supplied with a remote control unit. This is pocket-sized and can be used to adjust volume and set the T switch. It can also, however, be used to make some significant configuration adjustments to suit specific circumstances. Because of the physical size of the remote control unit and because it can be operated while in view of the user, making adjustments to a hearing aid in this way is much easier than when making adjustments on the aid itself while it is in or behind the ear.

Cost range is currently broad, mainly depending upon whether the aid is analogue or digital. This variation is likely to narrow as digital aids become more common. Analogue aids are available for approximately $900 each and digital aids may cost up to $2500 each. If a person requires an aid for both ears, the cost is doubled. Remote control units cost from approximately $200. Importantly, people under the age of 21 and those receiving a Social Security pension with Health Benefits are eligible for free service from Australian Hearing and approved service providers under the Commonwealth Hearing Service Program. This includes full audiological assessment and provision of hearing aids and rehabilitation strategies. Eligible clients can also have a maintenance package for a $30 annual fee as at 2000. this includes repairs and batteries.

Modern aids can be very small, often being placed behind and even in the ear of the user. Behind-the-ear (BTE) aids are usually more powerful than in-ear aids and are therefore more effective for people whose hearing loss is more severe. BTE aids are also more visible on people with short hair. This can make them less appealing to those who are self-conscious. On the other hand, that an aid is visible can serve to explain to others that the person has a hearing loss and, hopefully, lead to considerate interaction.

Advantages

Communication for people with mild to severe hearing loss can be considerably improved with hearing aids, as they make previously inaudible speech sounds audible. Even in more difficult environments, those who are prepared to apply themselves to learning to adjust and interpret the aid can often benefit. The aid can be inserted and removed quickly and easily. When used in conjunction with various ancillary equipment discussed below, hearing can be improved in a number of circumstances. These include large venues such as lecture halls, listening to electronic media and using the telephone.

Disadvantages

While hearing aids can improve comprehension of sound in ideal circumstances, they do not provide normal hearing. Firstly, with mild to moderate hearing losses, directional hearing may be poorer, although ongoing research and care in the fitting process can often help to resolve the problem. Secondly, understanding speech in a group can be very difficult. An additional problem is that sound quality deteriorates markedly as the distance between the speaker and the hearing aid increases. Comprehending speech is more difficult in a noisy environment, as the hearing aid amplifies all sounds within its range and speech sounds cannot be separated from noise.

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Body aids

Description
This relatively large aid can be carried in a pocket, clipped to an item of clothing or hung around the neck. Sound can be received through an in-built microphone. If preferred (depending on circumstances and need), a microphone cable can be plugged into the aid and the microphone clipped, for example, to a lapel. Another cord carries the signal from the aid to the ear.

Due to their bulk, body aids have diminished in popularity as smaller options have become available. However, there are still circumstances in which they are most suitable. They are more robust than other types of aid. This makes them especially suitable for children. The aid is also more powerful than others and is therefore often more suitable for people with a profound hearing loss than the other types. It also has a larger battery, which lasts longer. A body aid also boosts low frequency sounds better than other types of aid. The risk of feedback is also reduced due to the greater distance between the microphone and the ear. Another benefit on some models is the ready option for connecting directly to various sound sources due to the availability of the microphone jack.

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Behind-the-ear aids

These aids combine quite high performance with small size. The aid, including microphone, is one small, crescent-shaped unit which rests comfortably behind the ear. A hook shape at the top of the aid secures it to the ear. A short plastic tube carries signals from the aid to the ear. The end of the tube entering the ear is held in place by the ear mould, discussed above. Some people do not like BTE aids due to embarrassment caused by their being seen by others. However, less self-conscious people believe it to be beneficial that people can readily recognise their hearing loss. These aids can include more features than smaller ones, are more robust and easier to repair.

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In-the-ear aids

Description
These aids are much smaller than BTE aids and are placed in the pinna (the visible part) of the ear. The aid is contained within the ear mould. In-the-ear aids are not as powerful as BTE aids and, if high volume is required, battery life is very limited. Some people prefer these aids for cosmetic reasons. However, they are only effective for people who have mild to moderate hearing loss. That is, they will not be effective for people who have severe or profound loss.

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In-the-canal aids

Description
As the name suggests, the aid is placed in the ear canal. The microphone and (extremely small) controls protrude from the canal. It is often not possible to fit a telecoil to this type of aid. This may be an important consideration. The aid is usually custom made and has to be returned to the manufacturer for repair.

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Completely-in-the-canal aids
Description

These are the smallest type of hearing aid and are extremely tiny. A fine thread is required to remove the aid from the ear. While a remote control unit can be of benefit for other aids, as discussed above, one is absolutely essential to control completely-in-the-ear aids. A telecoil cannot be fitted to these aids.

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