By Caity Tarbert, Tests.com Contributing Writer
Hearing tests are one of the most basic assessments given as a part of a routine doctor's visit or school physical. From birth to adulthood, individuals should have their hearing tested regularly in order to ensure optimal hearing. There are a large variety of hearing tests, but the object of each test is to measure the ability of sound to reach the ear, and they assess conductive and sensorineural hearing loss. Conductive hearing loss occurs when sound waves have difficulty moving through the outer ear, middle ear or eardrum. It can occur separately or in combination with sensorineural hearing loss, which is caused when the inner ear or the nerve pathways from the inner ear to the brain are damaged.
How Different Hearing Tests Work
Sound is categorized in terms of frequency and intensity. Frequency refers to whether a sound is high or low and sometimes referred to as pitch. It is measured in vibrations per second, or Hertz. Intensity, or loudness, is measured in decibels.
The most common types of hearing tests are:
- Whispered Speech Test
- Pure Tone Audiometry
- Tuning Fork Test
- Speech Reception and Word Recognition Tests
- Otoacoustic Emission Test
- Auditory Brain Stem Response Test
Whispered speech tests are administered by a health professional. The patient covers the opening of one ear with a finger. The practitioner stands one or two feet behind the patient and whispers a series of words. The patient then repeats the words back to the tester. Each ear is tested separately.
In pure tone audiometry, the patient wears headphones and listens to a series of tones that vary in pitch and loudness. The patient indicates whether or not they are able to hear the tones. Again, each ear is tested separately.
Tuning fork tests are exactly what their name describes. A health professional strikes a tuning fork causing it to vibrate and produce a sound. This test determines how well sound is able to move through the ear.
Speech reception and word recognition tests measure one’s ability to hear and understand conversation. The patient is asked to repeat a series of simple, two or three syllable words spoken in different degrees of loudness. These tests distinguish conductive from sensorineural hearing loss.
Otoacoustic emissions tests are used most commonly on infants. The test involves placing a small microphone in the baby's ear canal. When sound is introduced, the microphone detects the inner ear's response to the sound.
Lastly, auditory brain stem testing detects sensorineural hearing loss, and is used most often with infants and small children. Best done while a child is sleeping or sedated, small electrodes are taped to the child’s forehead and behind each ear. Clicking noises are sent through small earphones the child wears, and the electrodes record the brain's response to the noises. The responses are tracked on a graph.
There are no risks associated with any of the above hearing examinations.
Hearing Test Results
The normal frequency range for the human ear is anywhere from 16 to 20,000 Hertz. The normal decibel range for adults is zero to 25. For children, the normal range is zero to 15 decibels.
If a patient fails a hearing test, the health professional will usually run a second screening to ensure there were no misunderstandings of instructions or other errors unrelated to hearing ability. This retest is especially important with school-age children. If the second test also shows hearing loss, the patient will be referred for an audiologic assessment and further medical testing.
Preparation for Testing
Hearing tests do not warrant much preparation other than a mental review of any hearing trouble that a patient has experienced prior to the test. Patients should tell their health professionals if they have experienced any hearing difficulties or are on specific antibiotics that may affect hearing. Additionally, it is wise to steer clear of loud noises for 16 hours prior to testing to avoid any skewed test results.
Have you had difficulty hearing, or would you like to make sure your hearing levels are up to par? Check out our Hearing Test Directory to find a health professional in your area. To learn more about hearing tests, read our interview with hearing test expert Suzanne Yoder.
Source: American Speech-Language-Hearing Association; asha.org/public/hearing/testing/assess.htm