Thursday, January 30, 2014

Uses Of An Audiometer As A Diagnostic Tool In Audiometry

By Marissa Velazquez


Hear loss and other disorders related to the sense of hearing are usually monitored using an instrument called an audiometer. It is calibrated with standardized units of measure to obtain the accurate results concerning the disorder. The test requires to be done in a room that is quite and is fitted with soundproof material. The patient is usually given a set of headphones to put on the ears. He is then expected to remain seated and be calm.

Sound relayed from the machine to the patient is done at different frequencies and intensities. The patient is required to respond whenever he hears the sound by either raising his hand or pressing a button. The hand raised has to correspond with the side of the ear that has heard the sound. This is repeated until the sound is very faint. The reading is then examined for any abnormality then recorded on an audiogram.

For a person to lose his ability to hear, he could be suffering from some conditions and in rare cases some people are born with this problem. Acoustic nauroma is presented in form of a tumor that grows slowly in the cranial nerve. This nerve is very sensitive for hearing and providing balance. When this condition occurs it can also cause facial paralysis.

A damaged eardrum or ossicle can cause conductive hearing loss. Damaged vestibulocochlear nerve can result to Sensorineural hearing loss. Sometimes a person can experience buzzing sounds which are also called tinnitus. Vertigo is another condition if not managed properly can result to hearing loss.

There are a number of tests than can be done to check for hearing ability. This are carried out according to the type of patient and the reason the test is to be done. The type of patient can be a newborn baby, young children or even adults. Children are not able to say when they have hearing problems. The audiologist has to use special equipments to test them. The principle followed in testing children is the same but the way of doing it may vary to be able to obtain more accurate results.

An otoacoustic emission test is used to check for hear loss on babies. It is a simple test that is not painful and is very fast. It comprises of a small earpiece which has a microphone and a tiny loudspeaker. The earpiece is placed in the ear. Clicking Sound is produced by the loudspeaker and relayed to the cochlea which in turn sends it to the ear canal to be heard through the microphone.

A case where no sound is heard could mean an hearing problem though other factors have to be ruled out. These factors can be an unsettled child, a noisy room or even the presence of some fluid in the ear after birth. The test has to be done several times and if not satisfactory another more sensitive test called automated auditory brainstem response is done. Both tests have to be done when the child is asleep to avoid interruption.

Reinforcement audiometry is the technique recommended for testing young children. Using speakers, sound is relayed to the testing room and the child is expected to respond by turning towards the direction of sound. The audiologist rewards the child to motivate him as he performs the test repeatedly. The frequencies are altered at different levels to establish if the child can pick even the lowest sound. Testing older children and adult is different as a pure tone audiometry technique is employed. This includes the use of an audiometer to transmit sounds through a headphone in varied pitches and levels.




About the Author: