How hearing aids work
Most modern digital hearing aid have one or two microphones, a loudspeaker (often called “receiver”), a battery, and electronic circuitry. The “brain” of the hearing aid is a small but extremely powerful digital chip that processes and amplifies sounds picked up by the microphone which are then played back through the loudspeaker. This is how a hearing aid processes and amplifies sound:
- The microphone picks up sound and converts it into an electrical signal that is transferred into the digital signal processor (DSP), where the electrical signals are transformed into a digital code (consisting of “0” and “1”).
- The DSP executes a number of signal processing steps, like removing noise signals and increasing speech. The resulting digital output is transformed into an electrical signal and transferred to the loudspeaker.
- The loudspeaker converts the electrical signal into audible sounds and feeds them into the ear.
The hearing care professional (HCP) programs the hearing aid with an external computer and can individually adjust it to the needs of the client. Digital hearing aids can be programmed with multiple programs that can operate automatically or be activated by the wearer (e.g. programs to adapt to loud or soft sound, speech or music, quiet or noisy environments) and feature feedback suppression, noise cancellation, etc.
The technology behind hearing aids has improved greatly in the last years. You might have not heard about it, though, since hearing loss related issues are still not much talked about. In order to close this gap, the following list provides you with information on the latest generation hearing aids:
| Past generation hearing aids | New, state-of-the-art-hearing aids |
|---|---|
| Analog | Digital |
| All-over amplification | Specific amplification of sounds that are not audible anymore to the individual user, whereas loud sounds are not amplified. Amplification only in frequencies of individual hearing loss |
| Fixed program | Individual programming and fitting |
| Large and visible | Small and invisible |
| Beige colored, sitting on the pinna | Variable colors for invisible behind-the-ear hearing aids to match hair or skin color and dark colored in-the-ear models (matching the dark of the ear canal) and practically invisible |
| Stiff, heavy and uncomfortable | Slender build, lightweight and flexible |
Most relevant features to look for in a hearing aid
There are many different models from various manufacturers available in the market. Ask for these features in order to make sure you get a state-of-the-art model:
Directional microphones
Directional microphones improve understanding of speech in noisy environments. They pick up speech coming from the front and reduce noise coming from the side or back.
Digital signal processing
Digital hearing aids can analyze the hearing situation you are in and react accordingly. They can distinguish between quiet situations, speech in noise situations, or music and apply an optimized setting for that very situation. A program for music should be included, because music differs greatly from other sounds.
Noise cancelers
To further improve the listening comfort, a hearing aid should at least feature cancelers for impulse noise (e.g. the clattering of plates), general noise, wind noise, and feedback.
How to get a hearing aid
