Our senses of taste, smell, touch and sight all depend on chemical reactions within the body, but hearing is a completely mechanical sense that relies entirely on the movement of the small and intricate membranes and bones inside the ear that work together to enable hearing. If any of these elements is damaged, hearing cannot occur.
Deafness – the loss of the ability to hear in one or both ears – is a reality that nearly 280 million people across the world have to live with.
Hearing is a very intricate process, but in simple terms the following happens to cause us to hear: the outer ear directs the sound waves into and through the ear canal where the sound waves reach and vibrate the tympanic membrane or eardrum; the ossicles, a group of very tiny bones in the middle ear that are connected to the ear drum, are moved by this vibration and amplifies the force of the soundwaves by 22 times as it is passed on to the spiral shell-like cochlea in the inner ear, where the physical vibrations is translated into electrical impulses that the brain can recognise and interpret as sound.
Malformation of the inner ear, the part where the cochlea is located, is the cause of most cases of inherited deafness.
Because of their small size and delicate nature, the mechanisms inside the ear are extremely vulnerable to damage. About a quarter of all acquired hearing loss results from ongoing exposure to loud noise. The ear is also vulnerable to infectious diseases such as mumps, chicken pox and meningitis – in severe cases they can all cause deafness. Untreated ear infections also put hearing at risk.
If the cochlear nerve is damaged through trauma or accident, deafness almost always follows as the electric impulses can no longer reach the brain to be interpreted as sound.
Our Employee Wellbeing Programme (EAP) is available 24 hours a day if you want to know more about deafness.