The Work Of An Audiometer And Techniques In Audiometry

By Marissa Velazquez


An audiometer is a special instrument used to identify and monitor hear loss and hearing disorders. It has standard calibrations which help to obtain the best results of the condition. Audiometric tests are carried out in a quiet soundproof room. Headphones are provided to the patient to place on his ears. The professional requests you to sit and remain calm.

The headphones are connected to a machine that produces tones under various frequencies or pitches and at different intensities or levels. The audiologist requires you to respond by rising of your hand whenever you hear a sound. This has to be done in a way that he understands when one side of the ear is not alright by raising the left hand if the left ear is okay and the same for the right ear and hand. Some professional however, provide a button that you can press. The results produced are then analyzed and recorded on an audiogram.

There are many conditions that have contributed to people losing their hearing ability. One of such condition is called acoustic neuroma. This is a slow growing tumor on the cranial nerve, which has the responsibility of the sense of hearing and balance. In addition to the loss of hearing ability, it can also cause paralysis of the face.

Damage to the eardrum also known as the ossicle is also associated with hearing loss. Malfunction of a part of the hearing system known as vestibulocochlear nerve has been associated with sensorineural hearing loss. You might occasional experience a buzzing sound known as tinnitus. Mismanagement of some conditions like Vertigo can also result in hearing loss.

Hearing ability can be established through a number of tests. The test is always dictated by the type of patient and the reason for the test. You may encounter patients who are newborns, young children or even adults. Because children may not tell or even realize when they have hearing problems, the audiologist is then expected to use a suitable method of diagnosis. The test principle is the same for children and adults but the process may vary to get accurate results.

An otoacoustic emission test is most preferred to test babies. This is because the test is simple to carryout, takes a very short time and the child feels no pain. It involves the placing in the childs ear a tiny earpiece attached to a microphone and a loudspeaker. A clicking sound is then produced by the speaker, which is transmitted to the cochlea. If the cochlea is functioning properly, the sound will be sent back to the ear canal and picked by 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.

Young children are tested using a technique called reinforcement audiometry. Speakers are used to relay the sounds in the testing room and the child responds by turning towards the sound outlet. Every time this is done, the audiologist has to reward the child to keep him motivated. The frequencies are changed at different levels to see if the child can hear even at the lowest sound. Testing much older children and adults is done by use of pure tone audiometry technique. An audiometer is used to transmit sounds through headphones at different pitches and levels.




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