Handy hints about ear moulds

The ear mould is an important part of a hearing aid. It directs the sound to where it is meant to go in the ear and should fit well and comfortably.

Feedback (or whistling) and discomfort are the two most common problems with ear moulds.

• Feedback
• Uncomfortable ear moulds
• Looking after ear moulds
• Summary

Feedback

Feedback is caused by amplified sounds from the hearing aid leaking out from inside the ear through tiny spaces between the ear mould and the ear, and then going back into the microphone of the hearing aid.

There are five things which can affect or cause feedback:

1. Degree of Hearing Loss
   Feedback is more common when the hearing aid is a powerful one; there is more sound to leak out. This is why a tightly fitting ear mould is so important for people with severe losses. Small children who are growing fast will grow out of their ear moulds more quickly than an adult, so some little children will need to have new moulds quite frequently if a good fitting ear mould is to be maintained. As their growth slows then ear moulds will fit better for much longer.
2. Ear Movement
   Small children’s outer ears are quite soft. When they move their heads the “seal” between the ear mould and the ear may be broken, leaving space for the sound to leak out. As they grow and their ears become firmer this becomes less of a problem.
3. Mould Material
   Soft materials ensure a better and more comfortable fit when used with powerful hearing aids. Unfortunately soft moulds shrink and deteriorate more quickly than the hard materials commonly used with lower gain hearing aids.
4. Ear Wax
   Excessive wax in the ear can also cause feedback by reflecting sound back out of the ear. If there is too much wax it will have to be removed by a doctor. Your audiologist can see if there is any build up of wax.
5. Tubing
   The plastic tubing of the mould can become brittle with age and split, allowing sound to leak out.

What can I do to stop feedback?
The best solution is often a new ear mould. While you are waiting for the new moulds to come back from the laboratory you may find that using a lubricant like Auragel will help by filling the spaces between the mould and the ear. You can get Auragel from your Hearing Australia centre. Alternatively, a light smear of Vaseline or KY gel on the mould can help.

If your child has ear infections or skin problems we recommend you check with your doctor first before using Auragel or Vaseline.

Can I get new moulds quickly in an emergency?
Urgent ear moulds can be made up quickly. Hearing Australia centres have a courier service to the ear mould laboratories, and large metropolitan centres usually have a daily collection. If the ear impression is taken just before the courier pickup it will get to the mould laboratory – and back to you – with a minimum of delay, usually within a week.

What can be done if there is a chronic feedback problem?
Your audiologist can ask the ear mould laboratories for “problem” ear moulds to be specifically handled.

Sometimes it’s a process of trial and error, but a solution can usually be found.

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Uncomfortable Ear Moulds

As already mentioned, people who wear powerful hearing aids need to have firmly fitting ear moulds. This is when sore ears can become a problem.

When the ear mould laboratory gets each ear impression they dip it in wax to smooth out any irregularities. If asked by the audiologist, they will put extra wax or “build up” around those parts of the ear mould where sound commonly leaks out causing feedback. While this often solves the whistling problem, it can cause pressure points and sore spots. It can be quite a delicate job, balancing build up to stop feedback without causing pressure points.

If an ear mould hurts, make an appointment to see your audiologist. Some trimming of the ear mould may be all that is required, or perhaps special instructions regarding build up and ear mould materials to the laboratory may also be necessary.

Ear mould materials
There are several different types of ear mould materials varying in softness and non-allergenic properties. Some people will do better with a particular type of ear mould material and your audiologist may try more than one type before finding the best one.

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Looking after ear moulds

Ear moulds should always be kept as clean and dry as possible. If ear infections or skin irritations are a problem, ear mould hygiene is even more critical.

Wipe the ear moulds with a damp cloth and remove any wax from the canal of the mould every time you take them out.

If your child wears behind-the-ear hearing aids, you can wash the ear mould with warm soapy water.

Washing a behind-the-ear hearing aid’s ear mould.

1. Carefully remove the mould from the hearing aid.
2. Wash in warm soapy water and then flow hot water through until the mould is clean.
3. Dry the mould thoroughly. Make sure there is no moisture in the tubing before placing it back on the ear hook.

The tubing must be dry inside before it is reattached to the hearing aid. An air puffer does this well and these are available from your local Hearing Australia centre.

You can use disinfectants in the washing water, though they can cause some mould materials to deteriorate more quickly.

In-the-ear hearing aids should never be immersed in water as the electronic components are inside the ear mould. Just wipe over with a damp cloth and remove any wax carefully with the small tool provided.

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In summary

Examine the ear mould regularly. If it is becoming loose in the ear, hard or discoloured, go to your Hearing Australia centre to check if a new one needs to be made. Hard tubing should be replaced before it splits.

Carefully clean the ear mould every time you take the hearing aid out.

If you do need a new mould back in a hurry, ask the audiologist to make the impression “urgent” and come into the hearing centre to collect it.

If there is a persistent problem with feedback or discomfort, make an appointment to discuss it with your audiologist. As early as you can, teach children how to look after their own ear moulds and keep them clean.

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Related articles

• Looking after hearing aids

Information provided by Hearing Australia. Reproduced with permission.