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Audiologists are health care professionals with clinical training and educational background in balance and hearing systems and their disorders. They assess hearing and balance, and provide treatment and consultation to individuals of all ages. Their work with clients typically focuses on the following:
Diagnostic Hearing Testing
Audiologists evaluate hearing in clients of all ages, from newborn to geriatrics. A series of separate tests are used that allow the audiologist to determine the type (where the problem is occurring), degree (severity) and configuration (pattern across frequencies) of the hearing loss. Certain tests are conducted in a soundproof room so as to ensure accurate test results.
Pure Tone Audiometry
Pure Tone Audiometry is used to determine the type and degree of hearing loss using the following tests:
Pure Tone Air Conduction Test
Used to determine the softest sound the client can hear at selected frequencies (pitches), from low to high. Ear phones or head phones are worn and sound signals are transmitted by air through each ear at varying degrees of loudness and pitch.
Pure Tone Bone Conduction Test
Used to test the sensitivity of the inner ear. A small vibrator is placed on the bone behind the ear; sounds are presented through the vibrator, traveling through the bones of the skull directly to the inner ear.
Both tests are displayed on a graph called an audiogram.
Speech Audiometry
Speech Audiometry is used to measure an individual’s ability to hear and understand speech. The following tests are included:
Speech Reception Threshold Test (SRT)
The audiologist will ask the client to repeat a list of common words while reducing the volume to determine the softest words the client can repeat correctly.
Word Recognition Test
The audiologist will ask the client to repeat series of words to determine the client’s ability to understand words at a comfortable listening level and at varying levels of loudness, in quiet or in the presence of background noise.
Most Comfortable Loudness (MCL) Level
The client is asked to indicate when the continuous speech is at their most comfortable level.
Uncomfortable Loudness Level (UCL)
The client is asked to indicate when the speech presented is uncomfortably loud.
Auditory Brainstem Response (ABR) Testing
Auditory Brainstem Response (ABR) Testing is used to measure the way in which the brain responds to sound, which will provide information used to determine nerve function and estimate hearing sensitivity.
Electrodes are places on the scalp and sounds are presented to each ear through earphones; the client does not have to respond and may simply relax during the test.
This test can be used to assess the hearing of individuals of all ages, including newborns.
Otoacoustic Emissions
Otoacoustic Emissions is used to test inner ear function.
A soft probe that contains a speaker and microphone is placed at the opening of the ear canal. Sounds are sent from the speaker and travel through the middle ear to stimulate the outer hair cells of the inner ear. The hair cells generate their own sound or sometimes called an “echo” which travels back through the middle ear and are detected by the microphone in the probe ear canal.
This test can be used to assess the hearing of individuals of all ages, including newborns.
Immittance Audiometry
Immittance Audiometry is used to measure characteristics of the middle ear and its structures.
A soft probe tip is placed tightly in the ear canal for the following tests:
Tympanometry
Uses air pressure and sound to measure the ear drum structure (to detect holes) or movement (to detect fluid build-up) and Eustachian tube function that supplies air to the middle ear space (like ear changes felt during air travel).
Acoustic Reflexes
Measures the pathway of sound to the brain and back to the middle ear muscle. A loud sound is presented to the ear canal and any movement from the muscle behind the ear drum in response to the noise will make the ear drum move and this can be recorded in the ear canal. This tests nerve function but also can give us information about the bones of the middle ear.
Auditory Processing Testing
Auditory Processing Testing is used to determine how the brain processes and interprets what is heard.
The audiologist will complete a full audiological evaluation, followed by a series of listening tests presented through earphones in a sound proof room.
Vestibular (Balance) Testing
Some audiologists evaluate vestibular (balance) function in clients experiencing vertigo, dizziness and/or balance problems.
A series of tests are used, including Electronystagmography (ENG) and Videonystagmography (VNG). These tests measure eye movements and may involve the patient watching or tracking a moving light or objects, insertion of cool or warm water into the ear canal or changes in physical movement. Abnormal “nystagmous” (eye movement) may indicate neurological or ear conditions effecting normal balance function.
Treatment and Management of Hearing and Vestibular Disorders
Based on a review of test results, the audiologist will work with the client to develop an appropriate treatment/management program. This may include:
- Recommending/fitting hearing aids as appropriate;
- Recommending other assistive listening devices i.e. FM systems, cochlear implants;
- Recommending strategies for individuals with auditory processing disorders, balance dysfunction or other disorders related to the auditory system.
- Recommending consultation with an otolaryngologist/Ear Nose Throat specialist if certain abnormal conditions are suspected.
For more information visit What is an Audiologist.