Around 37.5 million adults in the US report some degree of hearing loss. This accounts for around 15% of the overall population. The problem is mostly tied to age: as we get older, the intricate biological mechanisms through which we’re able to hear begin to deteriorate.
This presents a range of practical problems. We might have difficulty understanding people and holding conversations with them, which can lead to a sense of social isolation. We might fail to hear cues that might help us to avoid danger – like the sound of a reversing truck. We might find ourselves unable to enjoy the music we once listened to.
Fortunately, there are technological tools which help us to get around the problem, to some extent, and to minimise its impact on our quality of life. The hearing aid is undoubtedly the most effective and popular of these. There are audiologists all across the country who’ll test your hearing, and let you know whether a hearing aid is an appropriate solution.
What is a Hearing Aid?
A hearing aid is a device that slots into your ear. Its purpose is to amplify (that is, make louder) incoming sound so that it’s at a volume you can easily hear. This means that visiting relatives won’t have to shout to make themselves heard. The earliest forms of hearing aid were kinds of trumpets which collecting sound from a large area and funnelled it into a smaller one, thereby increasing pressure on the inside of the ear. Nowadays, the solution relies on electric amplification instead.
Types of Hearing Aid?
Hearing aids fall into several categories. There are Behind the Ear (BTE) hearing aids, which consists of an electric assembly behind the ear which connects to the inside via a soft length of tube. Then there are Completely In the Canal (CIC) hearing aids, which slot all the way into the ear canal.
Components and How they Work
You can think of a hearing aid as a miniaturised version of a PA system. A microphone picks up sound from the outside world, and turns the sound waves into an electric signal. At this point, that signal might be converted into a digital signal – which means that it can be processed to suit the needs of the hearer. You might want certain frequencies emphasised, for example, and others removed. Once this is done, the signal is converted back into an analogue waveform and passed to a miniature loudspeaker which plays the sound into the ear canal. All of this, of course, requires a power source – which is why hearing aids come with a very small battery.
