A hearing or audiometric test is done in order to evaluate an individual's hearing ability. We are able to hear because when sound waves reach the ears, they are converted into nerve impulses which are then sent to the brain. Sound waves are produced due to the vibrations of objects within the environment. These sound waves vibrate at certain frequencies and have certain amplitudes. The speed or frequencies of the sound waves determines the pitch of the sound. The volume of the sound is determined by the height or amplitude of the sound. The sound waves travel through the ear canal and beat against the ear drum which separates the middle ear and the ear canal. Once the ear drum is hit, it begins to vibrate. These vibrations travel to the bones in the middle ear, which also begin to vibrate. This has a magnifying effect on the sound which is then sent to the inner ear. The cochlea which forms the basis of our hearing ability is present in the fluid filled cavity of the inner ear.
The sound vibrations cause movement of the fluid in the inner ear and the cilia or hair cells of the cochlea begin to bend. This movement of the cilia produces nerve impulses which are sent to the brain through the cochlear nerve. When the nerve impulses reach the brain, they are interpreted as sound.
Hearing tests are used to detect problems in hearing. These tests measure the individual's ability to hear sounds that travel to the inner ear and also those that are conducted through the skull. In such tests, the individual is usually asked to respond to certain words or tones. There are various other types of hearing tests as well. In case the individual is able to hear a tone at a higher volume in only one ear or if he is able to hear only sounds of high decibel levels, then a problem in hearing may be present.
Depending on the type of test done, the results may be indicative of different hearing problems. In some case the cause of the abnormal results may be fluid build-up behind the ear drum. Scarring or rupture of the eardrum and damage to the bones of the middle ear can also interfere with an individual's hearing ability. You could undergo a thorough ear and hearing examination and have the doctor assess the severity of your hearing problem. The doctor would also advise you on the proper course of treatment. Depending on the problem and how it responds to treatment, you can then take the hearing test again.
Submitted by M T on March 5, 2010 at 01:34