25 Aug Audiology Evaluations
THE ASSESSMENT ITSELF: An audiologic evaluation is sometimes thought of as “just a hearing test,” but more than “just” the ability to hear sounds is involved. The audiologic evaluation consists of a battery of tests each providing specific standalone information. Yet, the tests complement one another.
The purpose of audiological evaluation is to quantify and qualify hearing in terms of the degree of hearing loss, the type of hearing loss and the configuration of the hearing loss.
With regard to the type of hearing loss, the loss may be conductive (a temporary or permanent hearing loss typically due to abnormal conditions of the outer and/or middle ear); sensorineural (typically a permanent hearing loss due to disease, trauma, or inherited conditions affecting the nerve cells in the cochlea, the inner ear, or the eighth cranial nerve); mixed (a combination of conductive and sensorineural components); or a central auditory processing disorder (a condition where the brain has difficulty processing auditory signals that are heard).
With regard to the configuration of the hearing loss, the audiologist is looking at qualitative attributes such as bilateral versus unilateral hearing loss; symmetrical versus asymmetrical hearing loss; high-frequency versus low frequency hearing loss; flat versus sloping versus precipitous hearing loss; progressive versus sudden hearing loss; and stable versus fluctuating hearing loss.
Audiological evaluation is also carried out for purposes of monitoring an already identified hearing loss. Once a particular hearing loss has been identified, a treatment and management plan is put into place. The plan may include medical or surgical intervention, prescription of personal hearing aids, prescription/provision of assistive listening devices, skills development through aural (audiologic) habilitation/rehabilitation, or simply monitoring of the condition through periodic assessment.
Once a treatment and management plan is in place, it is still important for an individual’s hearing loss to be checked periodically to determine its stability. Is it fluctuating? Has it improved as a result of medical intervention? Is it progressing? Have new conditions come into play that have affected the original condition?
It is also important that a person’s ability to hear using amplification (e.g., personal hearing aids and any assistive listening devices that are used in place of, or in conjunction with, personal amplification) be monitored and documented. This monitoring would include functional gain assessment, real ear measurement, electroacoustic analysis, listening check, and even informal “functional” assessment in the person’s typical listening environment (e.g., the classroom, the workplace, the home).
PHYSICAL EXAMINATION: The audiologist will look at the outer ear (the pinna) checking for any malformation. The audiologist will use an otoscope, an instrument that contains a light and a magnifying lens, to examine the ear canal and eardrum. The ear canal is examined for the presence of excessive wax (cerumen), or foreign objects (food, toys, pieces of cotton swabs, etc.). The eardrum (tympanic membrane) is examined for any perforation and signs of fluid or infection. The audiologist will look for any indicators suggesting the need for referral for a medical evaluation and/or treatment.
TESTS OF HEARING AND LISTENING: The audiologist will conduct tests of hearing tones . This is called pure-tone audiometry. The results are recorded on a graph called an audiogram. The audiologist will also determine speech reception thresholdor the faintest speech that can be heard half the time. Then the audiologist will determine word recognition or ability to recognize words at a comfortable loudness level.
TESTS OF MIDDLE EAR FUNCTION: The audiologist may also take measurements that will provide information about the status of the outer and middle ear. These are called acoustic immittance measures. Tympanometry, one aspect of immittance testing, can assist in the detection of fluid in the middle ear, perforation of the eardrum, or wax blocking the ear canal. Acoustic reflex measurement, another aspect of immittance testing, can add diagnostic information about middle ear function and hearing loss.
After the test battery is completed, the audiologist will review each component of the audiologic evaluation to obtain a profile of hearing abilities and needs. Additional specialized testing may be indicated and recommended on the initial test results. Audiological evaluation may result in recommendations for further follow-up such as medical referral, educational referral, hearing aid/sensory aid assessment, assessment for assistive listening devices, audiologic rehabilitation assessment, speech and language assessment, and/or counseling.
As you can see, an audiologic evaluation is much more than “just a hearing test!”