When Was Your Last Audiogram?
By Lisa Mackenzie, M.S.
WHAT??!! For those who are familiar with an audiogram, this reply is tongue in cheek. But for those who are unfamiliar with the term “audiogram,” the reply may represent genuine confusion. An audiogram is a graphic representation of a person’s hearing abilities. Adults are often remiss in taking preventative measures for their hearing health due to limited understanding of the audiological evaluation. So . . .
Comprehensive Audiological Evaluation
The audiogram is just one part of a comprehensive audiological evaluation. The first part of an evaluation consists of a thorough case history obtained from the patient.
Second, an otoscopic examination is performed which involves looking in the patient’s ear with an otoscope to rule out the presence of any obstruction (i.e. ear wax) and/or identify any physical abnormalities of the ear.
The third part of the evaluation is tympanometry which evaluates the integrity of the middle ear. Results of middle ear testing can identify middle ear fluid, ear drum perforations and Eustachian Tube Dysfunction.
The final portion of the evaluation includes the audiogram. Testing is typically completed in a sound-treated room. The softest levels that can be detected, also known as hearing thresholds, are plotted at various frequencies on the audiogram graph. Most hearing evaluations test frequencies from 250 Hertz through 8000 Hertz. These frequencies are most critical for speech perception. Speech audiometry is also measured to determine how loud speech needs to be in order to be heard and how clearly a person can understand and distinguish different words and sounds.
Interpreting Your Audiogram
The Graph – An audiogram has two axes. The horizontal axis represents frequency (pitch) from 250 Hz to 8000Hz. Frequency can be likened to the keys on a piano where sound gets higher pitched as you move from left to right. Vowel sounds are among the lower frequencies and consonants such as F, S, SH, and T are among the higher frequencies. The vertical axis of the audiogram plots the intensity (loudness) of sound in decibels (dB). The softest levels are at the top of the graph and the loudest levels are at the bottom.
Symbols on the Audiogram – Different symbols are used on an audiogram to represent the right and left ear and specify the test conditions. Testing with headphones/earphones is called air conduction testing because sound travels through the air of the ear canal to reach the inner ear. Air conduction results for the right ear are marked with an “O” and the results of the left ear are marked with an “X.” Bone conduction testing, in which a device is placed behind the ear in order to vibrate the mastoid bone, is marked with a “[“ or a “<” symbol.
Degree of Hearing Loss – The degree of hearing loss is determined by how loud a sound needs to be presented at a certain pitch for the person to just barely hear it. Hearing loss can be classified as mild, moderate, moderately severe, severe or profound. It is quite common to have varying degrees of hearing loss across the frequency range. A person can have normal low frequency hearing and a severe high frequency loss resulting in difficulty understanding or discriminating speech.
Type of Hearing Loss – There are 4 types of hearing loss; conductive, sensorineural, mixed (conductive and sensorineural) and auditory neuropathy. Conductive loss involves the outer and/or middle ear and can often be corrected medically or surgically. Sensorineural loss involves the inner ear and treatment options often include amplification through hearing aids or cochlear implants. Mixed loss may require both medical intervention and amplification. Auditory neuropathy occurs when transmission from the inner ear to the brain is impaired.
Many of the terms used during an audiologic evaluation can be foreign to a new patient. Let one of the audiologists at Riddle Hospital help you navigate this unfamiliar territory. They can help guide you to a better understanding of your hearing abilities and options for rehabilitation. Knowledge is power! Be an advocate for your hearing health and schedule a comprehensive audiological evaluation today.
For more information visit our website www.mainlinehealth.org/riddleaudiology
or call 484-227-3200
Jessica M. Bell, Au.D., Director/Doctor of Audiology
Alexa R. Lynch, Au.D, Doctor of Audiology
Denise E. Stewart, M.S., Clinical Audiologist
Lisa C. Mackenzie, M.S., Clinical Audiologist
RIDDLE HOSPITAL
Audiology & Hearing Aid Center
1118 West Baltimore Pike, Suite 207
Media, PA 19063
(484) 227-3200
mainlinehealth.org/RiddleAudiology
