What is audiometry; Audiometry is the name given to the hearing test that enables the measurement of hearing and the evaluation of hearing functions. It covers tests and measurements related to hearing.
Which Procedures are Performed in Audiology Laboratory?
Pure Tone Audiometry: (Pto) It is the most common ear test. It determines the minimum sound intensity (hearing threshold) that both ears can hear at different frequencies (thin and thick sounds). Anamnesis is taken from the person and the test is explained to the person. Before starting the pure tone threshold audiometry test, the person is told that he/she will hear signal sounds in different tones and to press the signal button on his/her hand when he/she hears them. After the test is explained, the test starts. The person is seated in a soundproof cabinet. The patient's ears are exposed to sound through a headset. The two ears are tested separately and the hearing thresholds are determined. When the person hears the sound, they signal by pressing the button on their hand. Thus, the level of sound heard is determined. Airway and bone conduction hearing levels are determined in this measurement. Airway measurements provide information about the hearing pathways from the auricle to the brain. The bone pathway provides information from the inner ear. Airway and bone conduction measurements also provide information about which part of the ear the hearing loss originates from. Airway thresholds are determined with the help of earphones worn in the ear, and bone conduction thresholds are determined with the help of a bone vibrator placed on the protrusion called mastoid.
After the hearing thresholds are determined, the thresholds are marked on the audiogram.
Speech Audiometry
Speech audiometry is a test that uses the human voice as a stimulus to make an evaluation. When performing speech audiometry, a microphone is given to the person and the person is asked to repeat the words I read. In addition, these test results give important information about the necessity of a hearing aid and how useful it can be. They are important scores to be evaluated about the type and model of the hearing aid to be applied.SRT SDS, UCL, MCL values are determined and the results are recorded and transferred to the computer.
Speech Reception Threshold (SRT)
It is the loudness at which the patient can correctly hear 50% of the words given to him/her.
The test is applied as follows;
Six words with 3 syllables are given 10dB - 15dB above the patient's pure tone average (SSO). If the patient repeats all of them correctly, the intensity is reduced by 5dB and another list of 3-syllable words is given again. If the patient repeats this correctly, the intensity is decreased by 5dB. If the patient answered, for example, 2 of the 6 words correctly, that is, if the patient's score falls below 50%, the severity we gave in the previous step determines the patient's SRT score and is recorded.
Speech Discrimination (SDS)
For this test, 25 monosyllabic words are read by adding 25dB - 40dB above the SRT threshold of the person. Each correct and incorrect word is counted and the correct answers are multiplied by 4% and the SDS value is determined. After the SDS value is determined, it is recorded.
Most Comfortable Listening Level (MCL)
The part between SRT and the uncomfortable sound level (UCL) is the patient's most comfortable listening level (SRT + 25dB - 40dB).The value is determined and recorded.
Uncomfortable Level (UCL)
It is the point at which the patient is uncomfortable with the given intensity; it is the sound intensity at which the patient cannot tolerate the given intensity. The value is determined and recorded.
Tympanometry: It is a test to measure the pressure of the middle ear. It is a painless and painless test. -50 to +50 is considered normal as the pressure value. Before starting the test, the person is informed about the test and the test is started. The person should not move or speak during the test. The pressure in the middle ear is measured with a probe inserted into the external auditory canal. Separate measurements are taken for the right and left ear. The values obtained are recorded. During this test, the external auditory canal pressure is changed and membrane mobility is checked while sound is sent to the ear. As a result, a graph and pressure value is obtained. After the values are recorded, they are transferred to the computer. As a result of the test; important information about the health and function of the eardrum and ear ossicles is obtained.
Acoustic Reflex; High sound waves coming from outside vibrate the eardrum and then the ossicles. If the sound intensity is excessively high, the stapes muscle, which is connected to the stirrup ossicle to protect the inner ear, contracts to prevent excessive movement of the stirrup bone and protects the inner ear. This is called acoustic reflex. Reflex values are measured by recording the movements of the membrane when the stirrup moves.
With this test, information is obtained about the degree to which the acoustic reflex pathways work against a severe stimulus. Separate measurements are made for the right and left ear and the values are recorded after determining the values.
With Which Complaints Do Patients Apply to Audiometry Center?
Feeling of pressure in the ear
Hearing loss problem
For what purpose are the devices in the audiology laboratory used?
Audiometers are electronic devices used to measure hearing sensitivity. With these devices, sensitivity to pure sound and speech sounds can be measured.
Impedance meter (tympanometer device);
- Tympanometry Test
- Acoustic Reflex Test
