What is the hearing test and how is it performed?

A hearing test is a painless, non-invasive investigation that measures somebody’s ability to hear various audio pitches, sounds, or frequencies. This science of testing hearing is known as audiometry and is now a highly skilled process, thanks to the wonders of modern medicine.

Audiometry is required for a wide number of different reasons. Some of these include, for example, patients who have a tumour in or around the ear. It is required to monitor hearing before and after certain types of surgery and can also be used to assess whether or not a person needs hearing aids.  

How does a hearing test work?

The human ear comprises three distinct parts: the outer, middle, and inner ear (Please see Fig. 1). Testing can detect whether as person has sustained damage to the nerve or cochlea or conductive damage to the eardrum or the tiny ossicle bones. There are several different types of hearing test. https://www.phonak.com/uk/en/online-hearing-test.html

 

Anatomy of the human ear

Figure 1. The outer ear collects sound waves and funnels them down the ear canal to the eardrum. When sound hits the eardrum it vibrates. These vibrations are passed along small bones known as ossicles, which are located in the middle ear. These bones transfer the vibrations to the inner ear – which is filled with liquid and lined with microscopic hair cells. The vibrations make the liquid and the tiny hairs move. This movement then generates nerve signals that are sent to the brain. The brain interprets these signals as sound.

A basic hearing test measures the softest audible sound that can be heard by the patient. During this test the person is required to wear earphones and listen to a wide range of sounds.  The volume of sound is measured in decibels (dB). For example, a whisper measures about 20 dB while loud music ranges from 80-120 dB.

Other hearing tests include a word recognition test. This measures the patient’s ability to distinguish speech from other background noises. This test is particularly helpful in deciding whether the patient requires a hearing aid.

The hearing test is performed in a sound-proof room and the person is required to wear equipment that his connected to a device that transmits sounds to each ear in turn.  In some tests the patient is required to repeat the words that they hear. These words are usually of two syllables. In the second stage of the test, the patient is required to repeat a list of one-syllable words. The volume of this list does not change.

There is also a test known as a tympanometry test, which is used to detect problems such as the build-up of fluid or wax in the ear. This test is also used if the patient is suspected to have damaged one or both or their ear drums.

During this test a soft plug is placed in the ear.  This plug changes pressure and can track the patient’s responses to various levels of sound and pressure. Movement of the eardrum is measured as well as the reflexes of the tiny muscles attached to the ossicles.

What does a hearing test show?

Basically, audiometry charts the patient’s ability to hear different tone frequencies in both ears.

What happens during the test?

1.      Earphones will be placed on your head.

2.      You will be asked to sit still and not talk.

3.      The audiologist will ask you to raise your hand when you hear a sound.

4.      you may be asked to push a button or make some other sign that you have recognized a sound.

5.      The audiologist will record each tone at the lowest possible volume that you were able to hear it.

 

 

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