How Do Hearing Aids Work?

Time to Read: 8 minutes

When looking for hearing aids, you’ll first want to know the answer to one simple question: “how do hearing aids work”?  Understanding the function of any product you buy is essential to getting the best quality for your money—finding the best hearing aids relies on that same principle.  There are many different types of hearing aids out there, but the basic functionality remains the same across the boards, with minor tweaks here and there for form, aesthetics and precision.

  • Choosing the Right Types of Hearing Aids
  • The Microphone
  • Electronic Amplifier
  • The Receiver / Speaker
  • The Power Supply
  • Digital versus Analogue

In order to help you choose the best hearing aids that will increase your quality of life by boosting the sounds you hear, it's important that you understand how they work.

The main parts of a modern digital hearing aid:

There are four main components of all hearing aids currently available on the market.  They are:

  1. A microphone which picks up the sounds from your environment and then converts them into electrical impulses.  These electrical impulses—or signals—are then sent to the amplifier, which is a computer chip dedicated to sound, in a modern hearing aid.
  2. The amplifier boosts the volume of these electrical signals, making it easier to hear. In the devices with the top hearing aid features, the amplifier also cleans up the signal, removing noise and improving speech. The amplified and cleaned signals are then sent to the receiver and speaker after the digital processed signal is converted back to electrical impulses.
  3. The receiver or speaker inside of hearing aids converts the amplified electrical signals back into sounds and then sends them directly to the ear where the natural hearing process takes over and the brain receives the impulses.
  4. To keep this process working, a battery is needed inside of the hearing aids. This can be a little replaceable battery cell or a built-in rechargeable battery for some hearing aids

So essentially, all a hearing aid really is is a tiny amplifier, kind of like the one's guitars or PA systems use.  Let's take a closer look at the four components to better understand which types of hearing aids make the best hearing aids.

The hearing aid microphone

Sounds waves are actually vibrations of energy which are floating around in the air.  Just as the waves you make in a pool diminish in power the further away they get from the source, the further away from the source (e.g. a mouth, a radio, a television) sound waves get, the weaker they get.  In order to make these vibrations louder again, a microphone must pick them up and convert them from the sound waves into electrical impulses or signals.  In the best hearing aids, the microphone is ultra-tiny and close to the ear to pick up the sound vibrations in the environment exactly how your ear does. Modern hearing aids can have two microphones, designed to pick up speech in front of you better than the noise around you. This can help tremendously when it comes to hearing better in noise.  Some can even wirelessly connect the microphones between the hearing aids on each of your ears, further improving your hearing in background noise. 

How Do Hearing Aids Work — Electronic Amplifier

Since the purpose of hearing aids is the amplification of sound, there must be an amplification device inside the unit.  Amplifiers don't actually turn up the sound per se, what they do is increase the strength of the electrical signal. The key here is boosting the strength enough so that it eventually becomes more audible when it is turned back into sound, but not so much that distortion occurs.  If the signal is boosted too much, the distortion produces sounds that are unrecognisable to our ears when compared to the source.  The best hearing aids have small amplifiers that don't require too much power. They also include special computer algorithms, cleaning up the speech and reducing noise, before sending it back to your ears. 

How Do Hearing Aids Work — The Receiver / Speaker

No, these aren't two different parts—the receiver is the industry term for a speaker.  The function of the speaker is simple, but crucial: convert the strengthened electrical signal back into sound.  It must do this without distorting the sound or weakening the strength of the signal, otherwise, all of the work done by the hearing aid thus far will be lost. While battery drain isn't really an issue with most receivers, you will want to make sure you only buy hearing aids that have speakers which rest very close to or inside your ear.

How Do Hearing Aids Work — The Power Supply

The most important part of the hearing aid is the battery because, without it, nothing would work. Batteries are the preferred source of power for hearing aids because they are inexpensive and can be changed or recharged fairly easily. The best hearing aids will have batteries that hold at least one week of continuous use charge, meaning the sounds won't go out unless you really neglect the batteries.  One of the most critical things to look for in a good battery is the constant delivery of a consistent voltage, from full charge to no charge—you don't want spikes and dips in your energy source. There are some good brands, like PowerOne and RayOvac and some terrible brands out there. So choose carefully. 

These days there are also several rechargeable hearing aid options available to choose from.


Other Considerations — Digital versus Analogue

While the time has really passed for analogue hearing aids, you should still understand the major problem with them: they amplify every sound in the environment equally.  That means you hear the planes above, the din from the cars whizzing by, the sucking of the vacuum cleaner and the incessant barking of the neighbour's dog all at the same volume you hear your grandchildren trying to tell you something.

You will be hard pressed to still find and purchase programmable analogue hearing aids which will allow you to change channels to adjust for different situations as per pre-programmed settings.  Of course, the much simpler solution is to buy modern digital hearing aids which provide a much clearer and effective sound quality.  The digital part of these hearing aids simply means that there is a computer chip inside which performs instant automatic analysis on both your level of hearing loss and the sounds coming in from the outside environment. They can then alter the sound in interesting and innovative ways to clear up the signal and reduce noise, before putting the sound back in your ears.

Digital hearing aids come with a slew of interesting features, but beware, there are only a few hearing aid features that actually make a big difference. Digital hearing aids also come with Bluetooth connectivity, which opens a world never even imagined with analogue hearing aids. 

To find out hearing aid prices, Australia residents can head on out to the store or just click here right now to find the widest selection on the best hearing aids on the market, all from the comfort of your own home.

The role of hearing aids

Hearing aids are designed to correct for the damage in your ears. Unlike with glasses the damage they are designed to correct is not limited to the lens, or eardrum in the ear's case. Your whole ear works a bit like the microphone to the brain. When the brain's microphone is damaged, as with hearing loss, it is deprived on sound. When this happens we find nerves start disconnecting in the brain due to a lack of stimulation. 

Hearing aids can reverse this deterioration in the brain, but only if used consistently.  So choosing the right one, which can help now and for years to come is critical to your success

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