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2 December 2020

Hearing-aid features explained

Discover the hearing-aid features that could make your life easier –and the ones you shouldn't waste your money on
Hearing aid 438498
WhichEditorial team

Hearing aids all contain essential parts, such as a microphone, amplifier, receiver (speaker) and batterybut what about the other features on offer? Our A-Z jargon buster explains the most common terms you'll come across.

While advanced features can sound exciting, remember that they can also make your hearing aids more expensive and complicated than necessary. Whether you need additional features depends on your lifestyle and type of hearing loss.

An audiologist should assess your needs and advise you on the features that might suit you, based on your individual needs and level of hearing loss. They should then recommend the best brand and model of hearing aid for you.

Once you've got an idea of what you need, our guide to hearing aid prices will show you how much you can expect to pay for the level of hearing aid you want. We've got detailed information from retailers so we can give you price ranges for the models they sell.

Different manufacturers have different terms for features, so we've tried to reflect this. They might deal with some aspects of the hearing aid – such as noise management and distinguishing speech from noise – in different ways. Don't be afraid to ask your audiologist/hearing-aid dispenser what a feature means or how the recommended features work.

Anti-phase feedback

Detects whistling and cancels out feedback. Also called feedback management, feedback cancellation and ultra-whistle-control manager, this is present in most basic hearing aids.

Automatic acclimatisation adaptation

The aid adjusts the amplification itself (rather than the audiologist doing it) as you get used to wearing it; a type of self-learning.

Automatic compression

This provides more amplification for low sound levels, preventing high sound levels from being intrusively loud.

Automatic noise detection/reduction

This is a common feature present in most hearing aids and it can reduce irritating background noise, such as the clinking of dishes. Also called transient-noise reduction and impulse-noise reduction.

Bands or channels

Most hearing aids divide the frequency range they support into bands or channels as a means of fine-tuning the hearing aid for the individual, making speech clearer and reducing background noise. More channels or bands can enable better tracking of the hearing loss pattern, if this is what you need.  

However, more bands doesn’t necessarily mean improved sound quality, although they can give your audiologist more flexibility in fine-tuning the hearing aid for your hearing.

Choice of listening programs

Most digital hearing aids allow you to switch between various settings for different listening conditions, and some adjust automatically. The Telecoil setting (see below) can be added as a program.

Control gain

You can adjust the amplification of certain sounds – for example, reduce traffic noise but still be able to hear birds.

Direct audio input

Direct audio input (DAI) is a way for a hearing aid to connect directly to other external audio sources, such as CD players, MP3 players, mobile phones or assistive listening devices. Direct audio input connection uses a 'direct input shoe’ (a little piece that connects to the bottom of the hearing aid).

You can then either connect the shoe through a direct input cable or an ‘ear level receiver’. It is important to note the direct input shoes are specific to the make and model of your hearing aid. Your audiologist should be able to advise you on which one is correct.

Direct Audio Input is not widely used as most digital hearing aids are now wireless.

Ear-to-ear directionality or wireless

If your hearing aids are wireless they will communicate with each other. Depending on the technology, they may also synchronise features, such as directional microphones to form a single hearing system, prioritising speech, and helping to reduce the need for you to adjust it manually. Also called binaural processing.

Frequency lowering

Your hearing aids take the higher-frequency or pitched sounds you should be hearing, and lower it to a frequency where you have better hearing. This can also be done through frequency transposition and frequency compression.

Low-battery indicator

A common feature, present in most hearing aids, which alerts you when it’s time to change batteries.


These are the means by which your hearing aid picks up sound.

Omni-directional microphone

A microphone that picks up sound 180 degrees around you. If you are wearing two hearing aids, this will pick up sound all around you – 360 degrees.

Adaptive microphone

Also called binaural multiband adaptive directionality, or comfort for speech in noise.

This microphone focuses on wherever the speech is strongest, amplifying it and reducing unwanted background noise. This would be useful – for example – in a car, where the people you're talking to might be behind you, or if you were in a noisy restaurant and the waiter stood beside you and spoke to you.

Directional microphone

Put simply, your hearing aid has two microphones – one facing forwards, and one backwards. In a noisy environment the back microphone can be switched off, so that the aid picks up and amplifies sounds in front of you. This makes it easier for you to focus on what you want to listen to in a noisy place and is especially useful for one-to-one conversations.

Nowadays, hearing aids have an ‘automatic’ program, where they can tell if you are in a quiet environment or noisy one and will change between different microphone modes, without you having to touch the aid. 

If you are used to having a hearing aid which lets you control which mode the hearing aid is in, your audiologist can set this up for you.

The audiologist can discuss with you your requirements, as in more challenging listening environments that are very noisy, you may be better off with a bespoke manual program you can use.

However, hearing aids won’t know exactly what you want to listen to, and so the reduction of unwanted sound can never be perfect.

Music programme

It can optimise the sound of music by using a different algorithm or sequence of sounds. Also called music equaliser.

Sound softener

It attacks and suppresses transient noise; most hearing aids have it.

Telecoil (also known as a loop)

You may have spotted the sign indicating a loop system, known as Telecoil, in banks or shops. Provided it’s working and switched on, it will enable you to hear more clearly in places with lots of background noise. You can also use Telecoil with telephones and mobile phones, but they must be hearing-aid compatible.

Most hearing aids have a Telecoil setting (although smaller ones may not; they may be smaller because the Telecoil has been removed) but you may need to get it activated by your audiologist first.

If you are having a custom hearing aid, it is important you ask your audiologist to have the Telecoil added, as it can not be added once the hearing aid has been made.

Tinnitus masker/combination device

A tinnitus masker is a device worn like a hearing aid. It generates extra low-level sound to help mask your tinnitus or reduce its perceived loudness. 

Some hearing aids contain a sound generator that plays a soft white noise (like a shushing sound) to help mask the tinnitus (combination device).

User-defined settings

Allows you to control how the device behaves.


These are tiny tunnels in earmoulds or custom-made hearing aids that help minimise the blocked sensation you can get from wearing something in your ears. Whether they are present usually depends on how well you hear low-frequency sounds.

Wax guard or trap

Most hearing aid styles have one of these unless you have an earmould. This helps keep the aid free of ear wax, which can cause problems. Your audiologist will teach you how to change this, as if it gets blocked with wax or debris it will compromise how you hear.

Wind-noise manager or reduction

If the wind is blowing across one hearing aid it will reduce the amplification in the low frequencies automatically to reduce the wind noise. 

Some wireless hearing aids can send – and enhance – speech to the other hearing aid. If there isn't speech, the hearing aids can allow you to be aware of the wind without it being painfully loud, by communicating with each other.

This more advanced hearing-aid technology can be especially useful if you spend a lot of time outdoors – for example, if you play golf.

Using your hearing aid with other technologies

Wireless hearing aids

Most hearing aids now are ‘wireless’, but check with your audiologist as some of the tinier hearing aids are not, but as they are positioned deeper in the ear canal they can pick up speech better.

Wireless hearing aids can ‘share’ information. The priority for the hearing aid is always speech, so now – working together, as a pair, rather than independently – they can make decisions to ensure the best possible sound quality is achieved.

A remote control allows the user to control their hearing aids without having to touch them. This device can be helpful with patients who have dexterity issues, such as arthritic fingers.

Hearing aids and mobile phones/smartphones

Whether you have a corded or cordless home phone, mobile or smartphone, you should be able to use it with your hearing aids in, rather than taking them out.

Most hearing aids have automatic phone settings. Your hearing aids will set automatically to the phone's bandwidth.

Holding the phone above the microphone of the hearing aid helps to hear the phone better. For phones without wireless technology, use your hearing aid's M (microphone) setting. 

This should amplify the conversation without introducing acoustic feedback (a howling or whistling sound). On some phones you can increase the volume rather than adjusting your hearing aid.

If you have difficulty using your phone, you can look for a phone that is hearing aid compatible: the phone communicates with the Telecoil/ loop system (see above).

For mobile phones, as long as your hearing aids are wireless – or smart incorporating Bluetooth technology – you can have a gadget that you wear round your neck, or in your pocket. 

This is often called a streamer or neckloop and pairs your hearing aids to multiple devices such as the TV or your mobile, piping sound into your ears when you press a button on the gadget.

Some hearing aids communicate directly with Apple products, such as the iPhone, without the need for an additional assistive device. Some newer hearing aids connect to all Bluetooth.

You can discuss these options with your audiologist, who should refer you on for more information – for example, to a hearing therapist who can advise on this type of equipment.

For more information about managing your hearing and hearing-compatible products, contact the RNID information line on 0808 808 0123 (freephone).

How long do hearing aids last?

It's up to you how often you have your hearing assessed and your hearing aids upgraded, but we'd suggest an appointment with your audiologist every three to six months for hearing-aid maintenance, and every three years for a hearing test.

However, when you’re buying privately this comes at a cost although most private suppliers will provide these appointments free of charge for at least the warranty of the hearing aids, usually two years. 

Check with your hearing-aid dispenser about the aftercare service they will provide you before buying your hearing aids.

Hearing aids should typically last three to six years, so you’ll need to budget for buying new ones. You’ll also need to factor in the cost of replacing parts, such as batteries and wax traps.

It's likely that your hearing loss will change over time although this is unpredictable. Usually, your hearing is quite stable and changes very little between one review and the next (around every three years) and hearing aids are flexible enough to be adjusted to changes in your hearing level.

Audiologists usually test hearing at 250, 500, 1,000, 2,000, 4,000 and 8,000 Hz.

If you notice significant deterioration or feel your hearing aids aren’t working so well, seek advice from your audiologist. They should be seeing you at follow-up appointments, so your hearing aids can be reprogrammed if your hearing deteriorates.