How do hearing aids work?

For centuries, people have been trying to find ways to combat hearing loss, but the first electric hearing aid was created in 1898. Since then, hearing aid technology has advanced rapidly and these devices are helping millions of people all over the world to hear more clearly. So how does the life-changing technology in a hearing aid work?

Although there is a wide range of hearing aids on the market, they all fall broadly into two kinds of technologies: analogue and digital.

Analogue hearing aids have largely been surpassed by digital devices, but you can still find effective analogue devices on the market. They work by capturing sound via a microphone and turning the sound waves into an electrical signal that is then fed back into the ear. Some analogue hearing aids can also detect whether a sound is too quiet and can amplify the signal, a feature you will find is described as ‘automatic gain control’.

The development of digital technology has enabled the next stage in the evolution of the hearing aid. A digital hearing aid has five main components: a microphone, a microchip, an amplifier, a battery and a receiver. The microphone, which is located on the outside of the device, picks up external sound waves and passes these through a sophisticated microchip that is able to monitor the sound and convert it into a digital signal. The amplifier adjusts the strength of the signal before it passes to the receiver, which changes the signal into vibrations that go into the inner ear. An internal miniature battery provides the power for the device.

The most important part of the digital hearing aid is the silicon microchip. This tiny chip contains millions of electrical components that can process incoming sounds with a high degree of efficiency, regulating the signal that passes to the receiver, enabling the user to differentiate between similar sounds with a high degree of clarity.

Hearing aid technology has come a long way from the intrusive and unreliable devices that many of us remember from the 1970s and 1980s. Modern digital hearing aids can be customised to suit an individual’s lifestyle and precise level of hearing loss and can be fitted in or behind the ear. There are even specialised versions such as CROS hearing aids that can deal with hearing loss in one ear, as well as Bluetooth hearing aids that enable you to make wireless calls from your phone or to stream music.

With a smart, digital hearing aid that can adjust itself to the environment, people with hearing loss can enjoy a seamless listening experience, at work, at home or on their travels.