The normal hearing occurs in the following way. It is known that the ear consists of three parts and the sound should pass all three parts to the brains. The outer ear consists of the outer, visible part and the canal. In the process of normal hearing, the outer ear takes the sound vibration which is sent to the middle ear through the canal. The middle ear has two components: ear drum and three tiny bones. The sound vibration creates motion in the three tiny bones of the middle ear. Then, the fluid, which is located in the inner ear or cochlea, begins to move. This motion leads to stimulation of the cochlea hair cells. Inside the cochlea, there are thousands of hearing receptors. Then the cochlea hair cells begin to bend forth and back, sending electrical signals to the hearing nerve which sends these signals to the brains where they are properly interpreted as sounds. (Presbycusis, 2012)
The major causes of presbycusis, or an age-related hearing loss, include some “gradual changes in the inner ear and hearing nerve”, heredity factor, some occupational hazards the individual face in the workplace, and the use of some types of medicine. Besides, it is found that presbycusis can be also caused by a number of diseases including heart disease, Atherosclerosis, Diabetes, High Blood pressure and others. It is also known that in some cases, the environmental chemical exposure causes hearing loss. (Causes of Presbycusis, 2012, para.1)
One of the sources of presbycusis involving the problem with the outer or middle ear is otitis media, or an inflammation of the middle ear that can produce hearing loss. In this case, the symptoms include the sensation of fullness in the ear, dizziness, ear pain and fever. The source of presbycusis involving the problem with inner ear is labyrinthitis or the inflammation of the inner ear which is developed by a bacterial infection. (Gates & Mills, 2005, p.265)
Presbycusis caused by disorders of the inner ear and auditory nerve leads to the loss of hear cells which serve as sensory receptions of the inner ear. In this case, an individual has sensorineural hearing loss. However, in case presbycusis is caused by different abnormalities of the outer and middle ear, the individual has loss of sound sensitivity. These abnormalities include reduced function of the ear drum, or the three tiny bones located in the middle ear. They fail to carry sound waves from membrane to the inner ear in a proper way. (Gates & Mills, 2005, p.241)
If an individual has a normal hearing now, his ability to converse with others will be affected by environmental factors including high-pitched and low-pitched sounds. It means that it is necessary to exclude such activities as listening to the radio during the conversation, or watching TV programs. Moreover, in the public places, such as restaurants, bars and so on, it is necessary to choose seats away from sound sources. Loss of hearing can seriously affect the life of any individual, both psychologically and physically. (Presbycusis, 2012)
Causes of Presbycusis. (2012) RD.com. Retrieved from:<http://www.rightdiagnosis.com/p/presbycusis/causes.htm#relatedinfotext>
Gates, G. & Mills, J. (2005) Presbycusis. The Lancet. Vol 36(6).
Presbycusis. (2012) National Institute on Deafness and other Communication Disorders. Official Site. Retrieved from:<http://www.nidcd.nih.gov/health/hearing/pages/presbycusis.aspx#tips>