How hearing aids work

• How do modern hearing aids work? 
• Why hearing aids can do more than simply “make things louder”
• Other technological aids
• The history of the hearing aid

Modern hearing aids feature automatic programs for all environmental situations, speech amplification, disruptive background noise suppression and feedback suppression. All this makes the lives of those with hearing loss far easier, whilst enhancing their quality of life.

Below you'll learn more about how hearing aids have developed, and how modern hearing aids work. You can also find out how hearing aids can do much more than simply amplify sound in the ear, and which other aids can help to improve speech comprehension and sound.  

Impaired hearing means more than simply hearing less well. It also means difficulties in understanding. Noises differ with respect to tone, with some being more shrill or some more buzzing. Certain sounds are typically perceived as unpleasant, or even painful. In such cases, „making things louder“ is not the right way to help people hear better again.
 

Determining the right volume

Technology for amplifying sound signals is vital. People with impaired hearing can only hear sounds above a certain volume, meaning these sounds must be louder than for those with good hearing. However, if everything were to be made louder, a noise such as a police siren would be absolutely unbearable. This is why hearing aid adjustment is used to determine the hearing aid wearer's discomfort threshold. This threshold represents the sound level beyond which sounds are perceived as unpleasant. For most people with normal hearing, this value is around 100 decibels (dB), although the values vary according to the individual.
 

Background noise and exact frequency ranges

In addition to general volume, a hearing aid must amplify the specific frequencies that the wearer can no longer hear very well. Digital hearing aids, which are now state-of-the-art technology, are able to compensate hearing loss in various frequency ranges in a precise and targeted way.
The real challenge – for both technology and humans – is to filter out background noise. During conversations in busy restaurants, for example, even people with normal hearing rely on some very complex processing mechanisms to single out a friend's voice. Modern hearing aid technologies feature special functions that significantly improve speech comprehension in such difficult situations.
In order to cope with difficult situations, modern devices also feature various hearing programs for different hearing contexts, such as restaurants or listening to music. Hearing aids also have several frequency channels, making it possible to adapt sound amplification individually to the wearer's needs. Background noise and unpleasant feedback whistling can also be suppressed.

To allow hearing aid wearers to enjoy problem-free hearing, hearing aids specifically amplify sounds that are important for communication and reduce disruptive sounds. This process is fully automatic in modern hearing aids.

Discover additional features in modern hearing aids.

Many behind-the-ear models have a T-loop (telecoil) or induction loop. This is useful during telephone calls as it transfers the speech signals from the telephone directly to the ear. This significantly improves sound quality and speech comprehension. With a telecoil, induction systems, such as those installed in meeting rooms, theaters, or churches, can be used without any additional devices. This allows speech to be received directly via the hearing aid, while disruptive background noise is filtered out.

Hearing aids with Bluetooth are able to receive speech and music wirelessly from other Bluetooth-enabled audio sources (mobile phones or TV sets) over short distances. In some cases, a small, additional device (streamer) is required, which is positioned between the devices to transfer the signals.

Today, there are also apps that can be used to control the hearing aid via a smartphone. This means the hearing aid can be controlled wirelessly.

More information about the potential functions and innovations in the hearing aids of the future can be found here. Alternatively, our expert audiologists are happy to show you the latest models and advise you on which is best suited to you.
If you are unsure whether or not you need a hearing aid, you might be interested in our free hearing test. If the test confirms that your hearing is impaired, we recommend you visit one of our branches or talk to your ENT doctor.

Once used exclusively by royal eavesdroppers, hearing aid use has only become popular in the last 200 years. Few people are aware that the first hearing aid for which a patent was registered was worn by Queen Alexandra of England in 1901.