Image credit: Howard Hughes Medical Institute
This is your ear. Granted, it's not the bit you usually see; this is an extreme closeup of a section of the cilia, one of the most important parts of your ear. But exactly how do you hear?
When you hear a sound, sound waves first enter your ear and hit your eardrum, vibrating three tiny bones (namely the hammer, anvil and stirrup). These bones amplify the sound and vibrate the cochlea (and the cochlear fluid inside). The fluid passes its vibrations to the cilia that line the inside of the cochlea - and these cilia are what translate the vibrations into electrical impulses your brain can interpret and 'hear'.
Prolonged exposure to high levels of noise (be it music or workplace noise) damages these cilia, and unlike the hair on your head, these tiny hairs grow once (when you are still an embryo in your mother's womb) and they never regrow. If the cilia is damaged, it cannot properly convert noise vibrations into electrical impulses, resulting in damaged hearing.
If you're at a loud gig or concert and you emerge with ringing ears, this is because the tiny cilia have been forced to vibrate at one of their resonant frequencies for too long. The 'ringing' is the sound of a cilia dying... And remember, cilia do not grow back.
Noise Induced Hearing Loss is the biggest cause of hearing loss in the United Kingdom. Hundreds of thousands of people in the UK suffer from various forms of hearing loss and its associated side effects, including tinnitus, headaches, insomnia and even depression.
Sadly, many thousands more people are - right this minute- doing permanent damage to their hearing, either through poor understanding or simple lack of knowledge surrounding hearing loss. The fact of the matter is that there are quite a few things we can all do to avoid damaging our hearing, and most of them are simpler than you'd think.