If you have hearing loss you may not be aware of it, especially if it has developed over time. Your family members or friends may be the first to notice a change in your hearing. For example, they may notice that you are having difficulty hearing what people are saying, especially when many people are talking at the same time or in the presence of background noise. Hearing loss determines how well you may process sounds.
How We Hear
The ear is a complex organ of hearing and balance. The hearing pathway is made up of five main divisions: the external ear, the middle ear, the inner ear, the auditory nerve and the brain. The hearing process begins when sound waves enter the outer ear and travel through the ear canal to the ear drum, causing the eardrum to vibrate. These vibrations are then transmitted to the first bone of the middle ear, the malleus. The sound waves are amplified as they are passed from the eardrum and malleus to the next two bones of hearing, the incus and stapes. As the stapes vibrates, sound waves are transformed into fluid waves in the inner ear. The inner ear is made up of a snail-shaped chamber called the cochlea, which is filled with fluid and lined with thousands of tiny hair cells which are attached to the auditory nerve. The movement of the fluid stimulates the hair cells, which then activate the nerve endings. When these nerve impulses reach the brain sound is heard and language is interpreted.