Hearing aids are the best solution for many people with hearing loss and should always be explored as an option before hearing implants. An estimated one in 10 adults in the UK would benefit from hearing aids – that’s four million people – yet only one person in 30 actually uses them.
How they work
Put simply, a hearing aid works by amplifying sound. Most hearing aids, including those routinely issued on the NHS, are now digital.
A hearing aid contains a built-in microphone that picks up sound and processes it into an electrical signal, using a tiny computer. This signal is then made louder and converted back into sound then transmitted into your ear. The hearing aid can be tailored to suit the level of your hearing loss. Increasingly digital aids adjust automatically to different listening conditions such as noisy or quiet environments, so you don’t have to keep making adjustments manually.
Who are hearing aids suitable for?
Hearing aids are best for people with mild to moderate hearing loss. They can also help with severe to profound hearing loss, though in this case you probably need additional help such as an assistive listening device for the telephone, lip-reading, and/or sign language.
The different types of hearing aids
There are several types of hearing aids. Most work through air conduction, when sound travels down your ear canal and middle ear to the cochlea in your inner ear. However, if you can’t wear this type for medical reasons or they don’t work for you, you may benefit from other types of hearing aids or from hearing implants which bypass your ear canal and send sound vibrations directly to your inner ear.
Behind-the-ear digital aids: This is the type of hearing aid that’s usually provided by the NHS. It sits in the back of your ear and a soft plastic tube connects it to an ear mould or, if you have an ‘open ear fitting’, to a soft earpiece at the tip of the tube. The open fitting is less visible than an ear mould. It’s suitable for mild or moderate hearing loss.
Receiver-in-the-canal (RIC) digital aids: Some audiology departments are now beginning to issue RIC aids, which look similar to an open-fitting hearing aid but also suit for severe hearing losses. The receiver is inside your ear canal rather than in the ‘housing’, the hard casing that sits in the back of the ear. A thin tube and tip connect it to the housing.
All-in-one digital aids
There are three types of hearing aids that have all their electronic parts in a moulded casing inside your ear with no wires or bits behind your ear. However, they are usually only available privately.
In-the-ear (ITE) hearing aids fill most of the concha, the bowl-shaped cavity just outside the opening of your ear canal. They are suitable for all degrees of hearing loss.
In-the-canal (ITC) hearing aids are a little smaller, so more discreet and suitable for mild to moderate hearing loss.
Completely-in-the-canal (CIC) hearing aids are the smallest type and almost invisible. However, they can be fiddly to handle and are only suitable for mild to moderate hearing loss. Also they may not be suitable for people who have very narrow ear canals.
CROS hearing aids
This type is designed for people who are deaf in one ear only. CROS stands for ‘contralateral routing of signals’. The hearing aid picks up the sound from the side with reduced hearing and sends it to your hearing ear.
BiCROS hearing aids
Similar to CROS, BiCROS are designed for people who are totally deaf on one side but also have some hearing loss in their better ear. They amplify sound from both sides and send it into your hearing ear.
Bone conduction hearing aids
These are designed for people who can’t wear conventional hearing aids because of skin problems or an abnormality of the ear canal.
They are also suitable for some people with conductive hearing loss, when sound is unable to pass freely through the outer and middle ear, perhaps due to a permanent damage. However, conventional hearing aids are usually tried first.
Bone conduction hearing aids bypass the outer and middle ear and send sonar vibrations directly to your inner ear through the skull. You wear a headband or specially strengthened spectacles that hold a small bone vibrator in place behind your ear. You can’t feel the vibrations but to work well the device needs to be pressed hard against your skull so can be uncomfortable to wear for too long. This sort of hearing aid tends to use analogue technology.
Bone anchored hearing aids
Bone anchored hearing aids (BAHAs) involve an operation to place a small titanium implant into the mastoid bone behind your ear.
A tiny titanium screw is inserted through the skin and into the implant and a small sound processor can then be attached to the screw via an abutment.
The processor collects sound waves and converts them to vibrations, which are passed through the implanted screw to the skull bone and on to the inner ear. The skin around the screw must be cleaned thoroughly every day to avoid infections.
Things to consider
The hearing aids available on the NHS are more visible than the smaller, discreet types, which are only available through private health care and can be quite expensive.
As with any device, there’s a certain amount of maintenance, cleaning and battery-changing
Possible benefits of hearing aids
Better understanding of speech and conversation, both one to one and in groups.
Improved ability to locate where sound is coming from.
Easier use of the phone.
Improved ability to hear in environments with background noise.
Less conflict with others over volume of TV and radio
Key features of hearing aids
Directional microphone system – Most hearing aids have two microphones, which can be switched on to pick up sounds in front of you, rather than to the side or behind you, for instance. This makes it easier to focus on what you want to listen to in a noisy place.
Feedback suppression – This automatically reduces the whistling that can be a problem with hearing aids.
Automatic noise reduction – This reduces some kinds of steady background noise, such as traffic.
Different listening programmes – These may help hearing in different listening conditions. Some hearing aids adjust automatically in response to different sound environments such as noisy or quiet.
Direct audio input and Bluetooth – These features enable your hearing aid to connect directly to other external audio sources such as mp3 players, mobile phones or assistive listening devices. This can be done either through a wire (direct audio input) or wirelessly through FM technology such as Bluetooth.
Loop setting – Public places such as cinemas, theatres, banks and ticket offices often have a loop system, which reduces background noise. To make use of it, you need to turn your hearing aid to the loop setting, which may initially need to be activated by your audiologist.
How to get them
If you think you have a hearing problem, see your GP first. They will be able to rule out any temporary, treatable causes for your hearing loss, such as a build-up of wax or an ear infection. Once temporary causes have been ruled out, your GP can refer you to an audiologist, a specialist who deals with hearing problems, for an assessment.
At present, there are no NICE guidelines for hearing aids. However, if tests show that you need hearing aids, you can get them free on the NHS, though certain styles – mainly the more discreet, all-in-one designs – may only be available privately.
Your hearing aid dispenser will inform you in length about all the important details like batteries, device handling and aftercare. Major hearing aid manufacturers are Amplifon, Bernafon, Widex, Phonak, Oticon, Starkey and Siemens.