Most people reach the ripe old age of 50 without any hearing problems, but others suffer a very slow and gradual hearing loss that may not be noticed for years. Certainly working in a noisy factory is one such cause. And listening to loud music is another. The ear is made up of three parts- the outer ear, the middle ear, and you guessed it, the inner ear. The inner ear is about the size of a small finger nail and contains about 15,000 nerve endings, called hair cells. When some of these hair cells are damaged, you have a permanent hearing loss. Damage to the outer and middle ears is usually temporary and can be treated by a doctor. more... See more text