Audiometry is a test that evaluates a person's ability to hear sounds of different pitch and frequency. This is a necessary evaluation if there is a loss of hearing capacity. There may be different reasons for the loss of hearing. If there is a tumor in the ear, the physician may advise an audiometry to get an idea about hearing loss or whether there has been any hearing loss before and after the surgery. Physicians recommend audiometry to determine whether hearing aids are needed or not.
The Human Hearing
Sounds vary in terms of intensity (loudness) and tone (speed of vibration of sound wave). The intensity of sound is measured in Decibel (dB) and the tone of sound is measured in Hertz. The human ear cannot hear sounds that are greater than 85 dB in intensity and less than 20 or greater than 20,000 Hertz in tone. The sounds of greater than 10,000 are categorized as highly pitched. There are some animals which can hear sounds of even up to 50,000 Hertz. The tone of human speech varies between 500 Hertz to 3,000 Hertz.
A sound wave travels through the eardrum and the middle ear into the inner ear. The ear can hear sounds only when the sound waves stimulate the neurological structure of the inner ear and lead the sound signals along the nerve pathways leading to the brain.
How Audiometry Test Works
The sense of hearing is a result of a chain of events that culminates in the middle ear receiving the sound and passing it to the brain. The three parts of the ear- outer ear, middle ear, and inner ear need to work in succession to produce a sense of hearing. Loss of hearing can result if there is a failure in any of these stages. Audiometry tests are conducted to determine the type of hearing defect.
Types Of Hearing Loss
Sensorineural hearing loss. It occurs when there is damage to the nerve. Cochlear bone conduction related hearing loss Conductive hearing loss arising out of damage to eardrums or ossicle bones.
It measures the least audible sound for a person. People are given earphones to wear and made to hear an array of sounds one ear at a time.
Types Of Tests Performed in Audiometry:
During an audiometric evaluation, a variety of tests may be performed:
Word Recognition Test
Audiometry may include a word recognition test as well. It tries to assess one’s ability to understand speech. If speech discrimination is poor, hearing aid is usually prescribed. Tympanometry Test Audiometry may also include a tympanometry test. This is done to detect problems like excessive build-up of wax/fluid, perforation in eardrum, damage to ossicle bones, tumors in the middle ear, etc.
Acoustic Reflex Test
This test is done to evaluate the neurological part of the hearing. It tests cranial nerves and brainstorms.
Audiometry test is an easy test. In case someone is experiencing any hearing problem, then discussing with Audiologist about this test is a good idea.