How Hearing Aids Work
Sound is energy produced when things vibrate and air is displaced. Your ear gathers this energy and funnels it through the ear canal until it reaches your eardrum. The eardrum is vibrated and three bones inside the ear transmit the vibrations to the cochlea, a fluid-filled organ containing tiny hairs named cilia. The fluid is agitated by the sound vibrations, moving the tiny cilia which send electrical signals to the brain that are interpreted as sounds.
The most common problem that arises with hearing involves the cilia, as the tiny hairs can become damaged, weakening their signals to the brain. This accounts for around 90% of hearing loss. Causes include fluid build-up, infections, exposure to loud noise or, most commonly, ageing. Hearing aids can help greatly with this type of hearing loss.
Early Hearing Aids
Until the introduction of electricity, hearing problems were helped using ear trumpets. These worked by funnelling sound energy into the ear canal, increasing the pressure on the eardrum to make the signals to the cilia stronger.
Electronic hearing aids were introduced in the early 20th century that amplified sound inside the ear using electric currents. Early devices used vacuum tubes, making them bulky and heavy, but the invention of transistors in the 1940s made smaller hearing aids possible, these could then be fitted behind the ear. These analogue hearing aids have been superseded by digital hearing aids, which came on the market in 1987 following the invention of microprocessors.
How Hearing Aids Work
Analogue and digital hearing aids use the same basic components: a tiny microphone, amplifier and loudspeaker. Sounds are picked up by the microphone and turned into an electric current, which the amplifier boosts. The strengthened current is sent to the loudspeaker which transmits the sound, via a tube, to the eardrum, making sounds detectable inside the inner ear before sending to the brain.
Digital aids work the same way, but are able to refine sounds and adjust them before re-transmitting them. Analogue hearing aids struggle to distinguish between sounds, but digital aids can easily adjust frequencies and control amplification, and the latest digital hearing aids can be fitted and tuned to very exact levels.
Further developments have led to hearing aids that fit completely inside the ear and are designed to remain there for long periods of time, with hearing aids such as the Phonak Lyric being worn inside the ear for up to four months. These hearing aids require expert insertion and fitting, but give far better results than previous models and are invisible to wear.
Call our experts today here at Help In Hearing 0845 222 0579
Or fill in our contact form for more information.