Audiology is a science that mainly deals with hearing problems. This discipline is involved in the rehabilitation of hearing and balance problems.
What is Audiology?
Audiology; It is formed by the combination of the words ‘audire’, which means hearing and hearing in Latin, and ‘logos’, which means definition and knowing. Audiology department; As the name suggests, it operates in areas such as screening and detecting problems related to hearing, preparing and training the tools to be used in the treatment process. Problems related to the structures in the inner ear and responsible for body balance are also within the scope of audiology.
Audiology has different sub-branches. According to the age group of interest, there are audiology sub-branches that conduct studies for pediatric, ie children or geriatric, ie advanced age group. Industrial audiology, on the other hand, is responsible for keeping the noise in the workplaces within the determined levels and taking measures regarding the hearing health of the workers working in this region. There are also audiology sub-branches specialized in the area of the balance system or speech and sound disorders.
What are the Tests Performed in Audiology?
Audiologists have a close relationship with Otorhinolaryngology (ENT) and neurology. When problems with hearing or balance are noticed in patients who apply to the ENT or neurology department, audiological tests can be applied to these patients. Audiological testing for the problem in patients is important in determining the source of the problem. Common tests in audiology:
Audiometry testing is often used to determine if a person has a hearing loss. In this test, the intensity and frequency of sounds that the patient can hear are measured. The intensity of the sound is measured in decibels (dB). For example, the sound intensity in whispering is approximately 20 dB, while the sound at aircraft take-off is between 140-80 dB. During the test, the person is listened to sounds with different decibel values from their headphones and the patient is asked to give a signal (such as raising a hand) when he hears the sounds. In this way, the intensity of the sounds that the patient can hear is measured. Another situation that is looked at with audiometry is the sound frequency range heard by the patient. Sound frequency can be expressed as the vibration of sound waves per unit time. Audio frequency; It is a feature that determines the tone, pitch, thin or thick sound of the voice. Under normal conditions, a healthy person can reach 20-20.000 Hz. It is expected to hear the sounds between Speeches made by humans are in the range of approximately 500-3,000 Hz. People with hearing loss may experience a decrease in the audible frequency range. Audiometry is a painless test that does not require any preparation. Hearing functions of the patient are measured by listening to various sounds through headphones.TIMPANOMETRY
Tympanometry is a test used to detect middle ear problems. The middle ear is the name given to the part behind the eardrum that goes up to the inner ear. Damage to this ear part, which is very important in hearing, can cause hearing loss. The tympanometry test is a test that is frequently used in situations related to hearing problems, especially in the pediatric age group. Before the test, the ear canal of the patient is examined with the help of an otoscope and it is checked whether it is normal or not. A device is then placed in the ear canal. This device is a device that records the changes in the movements of the eardrum under different pressures. After the device is placed, the air pressures affecting the eardrum are changed and the reaction of the eardrum to this change is recorded. During the tympanometry test, situations such as the patient’s speech and movement may affect the test result. Therefore, the patient should remain as still as possible during the test. The tympanometry test is done for both ears and is usually completed within a few minutes.
BAER / ABR TEST
The BERA (Auditory Brainstem Response) test is applied to see how the brain processes the sound heard. In this test, the person is told to sit or lie down comfortably. Afterwards, electrodes are placed on the earlobe and scalp of the person. These electrodes allow to measure the electrical activity in the relevant section. If the test is applied to a young child, the child can be given various medications to keep him calm during the test. This application is generally not needed in adults. After the electrodes are attached to the patient, various sounds are played with the help of headphones. Electrodes measure how the brain responds to the sound generated. The values recorded after the test are examined. Normally, an increase in the recorded electrical activity should be observed when the sound is heard. However, if the electrical activity in the patient is progressing smoothly without increasing, this may indicate a hearing loss. Conditions such as Multiple Sclerosis (MS), stroke, brain tumor that cause damage to the brain and nervous system can also lead to abnormal test results.
AUTOACOUSTIC EMISSION TEST (TEOAE, DPOAE)
Otoacoustic emissions are responses determined during hearing in people with normal inner ear functions. These responses occur as a result of the response of the hairy cells in the cochlea in the inner ear to sound. In the otoacoustic emission test, the presence of these responses is investigated by a small microphone placed in the ear canal. Otoacoustic tests; As they are simple, effective and non-invasive tests, they are frequently used in neonatal hearing screening. With this procedure applied to babies during sleep, it can be determined whether there is an auditory problem in the baby. If any problem is suspected as a result of this test in the baby, ABR test and some other tests are performed to try to reach the source of the problem.
Audiology also deals with problems with the center of balance in the inner ear. The VEMP test also measures the sound sensitivity of the structure in the inner ear called the vestibule. The VEMP test can be used in the differential diagnosis of dizziness.
ENG test; It is used to evaluate the parts of the inner ear that are responsible for issues such as positional state, orientation, and balance. ENG test; It is formed by the combination of various subtests such as oculomotor, positional, and coloric. In the caloric test, electrodes are placed under the patient’s eye on the top and sides. An electrode is also placed on the patient’s forehead. When the patient’s head is in a tilted position, the balance system is stimulated using hot and cold air. Electrodes measure the response of the inner ear to this temperature change and the nerves that pass near this structure. In the oculomotor test, the patient is asked to keep his head still. The patient is then told to focus on an object in the field of view and the object is quickly relocated. With this test, how much the patient can follow a target object with eye movements is monitored. In the positional test, the patient may be asked to turn his head quickly to the right and left, and the patient to stand up and sit quickly. Eye movements of the patient are followed during these movements. Positional test is a test that can be used in the diagnosis of vertigo or other dizziness.
Audiology takes part in the rehabilitation of hearing and balance problems as well as diagnostic tests. Audiology specialists are needed in many areas such as adaptation, use of hearing aids, vestibular rehabilitation after cochlear implant.
Hearing and balance problems are a serious condition that can affect people of all ages. With the recognition of these problems, diagnosis and treatment for the ailment, there is a serious increase in the patient’s quality of life. Every baby should participate in the hearing screening test, especially for newborns. Hearing in babies is also very important for language development. For this reason, early recognition of situations such as hearing loss or loss in babies and initiation of appropriate treatment ensures that the baby will encounter less problems in the future.