Audiometry Test

An audiometry test is primarily performed to assess the hearing ability of an individual. It may be done as a part of routine health check-up in healthy persons. However, audiometry becomes imperative to perform if the individual reports a noticeable loss of hearing. There can be multiple causes for hearing loss, which include:

• Birth defects
• Ear infections
• Ear injury
• Inner ear diseases
• Regular exposure to loud noises
• Ruptured eardrum

Sensorineural hearing loss may occur if the hair cells in cochlea do not function properly or if the nerve that carries auditory information to the brain is damaged. In a few cases, loss of hearing may be directly linked to brain damage. In such conditions, hearing loss is likely to be permanent. But usually, it ranges from mild to severe. 

Most health care organisations suggest that people who are exposed to prolonged loud music or occupation-based noise should undergo an audiometry test regularly. For example, adolescents who listen to music at a very high volume are prone to music-induced hearing loss and should hence go for regular checkups of their hearing ability.

No special preparation is required for an audiometry examination. The instructions for the exam will be given before the test, make sure that you follow them accurately. There are no risks associated with audiometry tests since it is a non-invasive procedure. 

Audiometry tests may begin simply with simple hearing tests in a doctor’s office. You may be asked to complete a questionnaire, which will enquire about the various issues that you may be facing with your hearing ability. Thereafter, a simple test, which involves hearing whispered voices or tones from an ear examination scope or tuning forks, may be done.
However, to obtain the exact measure of hearing, the following test will be done

• Audiogram: It is also known as pure tone testing. The doctor will ask you to wear earphones attached to an audiometer. One ear at a time is subjected to pure tones. You will have to signal every time you hear a sound. While administering this test, the doctor makes a note of the minimum volume that you require to hear each tone. In addition to this test, a bone oscillator will be placed against your mastoid bone (behind your ear) to test bone conduction. 
• Speech audiometry: Speech audiometry test helps to determine an individual's ability to detect and repeat spoken words at varying volumes, which are made to hear through a headset
• Immittance audiometry: Eardrum function and flow of sound passing the middle ear are determined using this test. For the test, a probe will be inserted into your ear and fixed over your ear so no air could pass through it. Air is pumped through the probe to change the pressure within the ear at regular intervals. The response of eardrum to varying sounds and pressures is then noted to determine the extent of sound conduction within the ear

The following would be classified as normal results:

• Ability to hear a whisper and normal speech without strain and discomfort
• Ability to hear the tuning fork through air and bone
• Ability to hear tones from 250 to 8000 Hertz at 25 decibels (dB) or lower in a detailed audiometry test 

If the results are abnormal, it may indicate the inability to hear high or low tones. When a person is unable to hear pure tones below 25 dB, he/she is said to have hearing loss.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational perspective and is in no way a substitute for medical advice from a qualified doctor.