Hearing aids are tiny in size but mighty in sound – but where does all that sound come from? Beyond their shiny shells, hearing aids have tiny computers working tirelessly to give you the best sound possible. Making up this electronic hearing wonder are 5 key components. Here’s how they work.
Main Parts of a Hearing Aid
It all starts with a microphone. The hearing aid microphone picks up incoming sound and sends it to an amplifier, which processes the sound by turning it from an analogue signal into a digital signal. This is then sent to the receiver which the delivers the sound to your ear in a way that is most true-to-life.
More on these 5 hearing aid parts:
- MICROPHONE: The microphone helps the hearing aid to pick up sounds from outside the ear. There are different types of microphones, both omnidirectional (sensitive to sound from all directions) and directional (sensitive to sound from specific directions).
- AMPLIFIER: The amplifier processes and strengthens the sound signal from the microphone and customizes it according to your individual needs and your hearing loss. It makes the sounds you hear recognizable without being distorted. The amplifier contains most of the hearing aid’s electronic components and circuits in a microchip.
- MICROCHIP: The chip is the nervous system of the hearing aid. Despite its micro size, the chip is incredibly powerful and can handle everything from signal processing to wireless communications. The chip means that hearing aids can be smaller and use less battery power.
- RECEIVER: The receiver or speaker converts the electrical signal into sound and sends it to your ear. How much sound comes out depends on its size. A severe hearing loss will often require a slightly larger hearing aid. Receivers also come with wax guards that help to keep moisture and earwax from entering the hearing aid.
- BATTERY: The engines of the hearing aid, batteries keep the whole thing running. How much power a hearing aid uses varies widely depending on its size, the number of features and the ways in which it is used.
Hearing Aid Features
Many hearing aids have more than just five main parts. These features can include:
- Telecoil – A telecoil is a small coil inside your hearing aids. The coil works as a small receiver which picks up signals from a loop system that acts as an electromagnetic field. Hearing aids with an activated telecoil can convert this electromagnetic field into a sound signal. Only the signal from the loop system’s microphone is amplified, and background noise is shut out.
- Audibility Extender – The Audibility Extender helps people with high frequency hearing loss to hear upper frequency sounds by moving these sounds to a lower frequency region where it is easier to hear them. The upper frequency sounds are important for hearing the “softer” sounds like /s/ and /t/ in women´s and children´s voices and high-pitched sounds like the “ping” of the microwave.
- Speech Enhancer – The Speech Enhancer is different from simple noise reduction systems in that it doesn´t just dampen noise – it also amplifies speech. When we listen to a sound, we are rarely in doubt as to whether it is speech or noise. The Speech Enhancer in modern hearing aids is able to distinguish the two in much the same way as our brains do – by using the fact that speech consists of a number of varying sound components that follow each other at brief intervals.
- Feedback Cancellation – Feedback Cancellation is a feature that aims to eliminate the whistling and howling caused by a microphone and speaker being too close to one another. With hearing aids, feedback whistling occurs when amplified sound from the ear canal leaks back to the hearing aid microphone. With less modern hearing aids, a whistle or squealing sound from someone’s ear could give a clear sign that they were wearing a hearing aid.
- The compressor – The compressor in a hearing aid is the feature that adjusts gain according to the current sound environment and the client’s hearing loss.
- Wireless communication – At Widex, we have developed our own technology to ensure that your hearing aids can communicate with each other – and with your TV, mobile phone or other devices.