Reading An Audiogram
Nov 16, 2021

Reading An Audiogram

Many health-related measurements are familiar to people, like perfect vision being represented as 20/20. However, how is healthy hearing quantified? Presented with the results of a hearing test, most people have no idea how to interpret what the graph—called an audiogram—reveals. 


An audiogram may initially look like indecipherable lines and symbols on a graph, but learning how to interpret it gives you a much better understanding of your hearing. Your audiologist uses it to determine recommendations for addressing your hearing loss, so knowing how to read your audiogram means even better communication between you and your audiologist in mapping a treatment plan for you. 


The goal of a diagnostic hearing evaluation

The goal of audiometric testing is to measure a person’s hearing ability across a range of frequencies, or pitches. Each ear is measured independently since hearing ability is not always the same in both ears. During a hearing evaluation, the audiologist will use headphones or earphones through which you listen for sounds, including beeps at various frequencies and recorded words. As you respond by depressing a handheld button when you hear beeps or by repeating back understood words, your hearing thresholds are plotted. A hearing threshold is the softest sound you can detect about 50% of the time. 


Understanding frequency and loudness

Look at the sample audiogram below. The horizontal axis (x) represents frequency, or pitch, from lowest to highest and is measured in hertz (Hz). Typically, the lowest frequency tested during a hearing diagnostic is 250 Hz; the highest is 8000 Hz. When you look at the x-axis that measures frequency, moving from left to right shows the frequency going from deep-sounding pitch to high pitched, much like the keys on a piano. Most human speech ranges from 250 to 6000 Hz. Vowel sounds (A, E, I, O, and U) are among the lowest frequencies and are responsible for loudness of speech. Consonants like S, F, SH, CH, H, TH, T and K sounds are among the highest frequencies and create clarity of speech. This is why hearing loss affects a person’s ability to understand words and conversations. If, for instance, a person has hearing loss that affects high frequency sounds, a word like “feet” begins to sound like “ee” as the letters F and T become indiscernible. Oftentimes, hearing loss occurs in the high frequencies first, which is why people often comment on hearing but not understanding. So, if you have been blaming your family of mumbling, it actually may be hearing loss.

The vertical axis (y) represents the intensity, or loudness, of sound and is measured in decibels (dB). A rifle being fired is a loud noise or a very high decibel sound. Rustling leaves are soft sounds or very low decibel.. Although the top left of the chart is labeled -10 dB or 0 dB, that does not indicate the absence of sound. A zero decibel reading actually represents the softest level of sound that the average person with normal hearing will hear, for any given frequency.


Understanding symbols on the graph

Several different symbols are used to indicate hearing thresholds on an audiogram, which create a quantitative “picture” of your hearing ability or loss. Testing with earphones or headphones is called air conduction testing because the sound must travel through the air of the ear canal to reach the inner ear. The organs of the inner ear then transmit the sound to the auditory nerve and on to the brain where sound is interpreted and assigned meaning. A red “O” denotes air conduction results for the right ear on an audiogram. The results for the left ear are marked with a blue “X." Bone conduction testing is completed by placing a device behind the ear on the mastoid bone. Sound is transmitted through the vibration of the mastoid bone, and results are marked on the audiogram with a “greater than (>) symbol” for the left ear and a “lesser than (<)” symbol for the right ear.


Air and bone conduction and speech testing allow an audiologist to more precisely interpret and diagnose hearing loss. Each symbol (X or O, < or >) on the chart represents your threshold for a given frequency and, when plotted, represents overall hearing ability. In the sample audiogram, the individual's thresholds from 250 Hz through 8000 Hz denote hearing below normal in both ears. A person with this degree of hearing loss will struggle when there is background noise, with softer speech and when there are no visual cues and may complain that people mumble. This person would benefit greatly from hearing aids. 


If audiogram symbols are essentially overlapping, hearing loss is considered symmetrical, or the same in both ears, like the sample audiogram shows. If the symbols do not overlap, your hearing loss is asymmetrical, meaning your ears have differing degrees of hearing loss. Your hearing loss also may show a pattern of loss that is generally flat or that is sloping or rising where some pitches are worse than others. Connecting the air conduction symbols makes the pattern obvious.


What is considered healthy hearing on an audiogram?

Take a look at the audiogram again. As a general rule, healthy hearing is represented in the blue shaded area above the 20 dB line that crosses the graph from left to right.* Any symbols below that shaded area, however, indicate hearing loss at those frequencies. Noteworthy is that hearing can be damaged by things like ear infections; medications; common household items like lawnmowers; noisy work environments; or a family history of hearing loss. (Find a list of common items that can cause hearing damage at johnsonaudiology.com/audiogram.)


Ultimately, when diagnosing and treating, your audiologist considers your audiogram, which represents quantitative measures, along with your perception of your overall listening challenges. Input from family members about communication difficulties also can be beneficial. Today’s sophisticated hearing aid technology is programmed to increase the sounds within the specific frequencies of your hearing loss. Thus, hearing aids are a great solution for restoring the sounds a person is missing, and early identification and treatment are keys to success.


A snapshot in time

Your audiogram is a snapshot in time of your hearing. It is a prescription for treating your hearing loss and a baseline for you and your audiologist. To monitor any changes in your hearing over time, routine testing is necessary. Knowing how to interpret your audiogram is a valuable skill, empowering you to make informed decisions. The information in this article is a basic interpretation of an audiogram. Audiograms can be more complex depending on the nature of the hearing loss or underlying medical issues.


*Some exceptions exist, such as when the person has very mild hearing loss but has tinnitus, or ringing in their ears.

Untreated hearing loss is changing your brain

By Jan Hollingsworth • 16 May, 2024
Research reveals that hearing loss actually rewires your neural pathways Your Amazing Brain Your brain is an amazing organ! This wrinkly, reddish-pink mass weighs about the same as your two-slice toaster, tipping the scales at about three pounds. Acting as a master control center, your brain enables every thought, breath, eye blink, heartbeat, movement—everything—that happens in your body. Rivaling the world’s most powerful supercomputer, your brain can download, process, and react in milliseconds to the tidal wave of information coming from your eyes, skin, nose, tongue, and ears. Neuroplasticity and Your Sense of Hearing Researchers have discovered that the human nervous system—made up of the brain, spinal cord, and a complex network of nerves—has incredible capacity to modify itself, both in function and physical structure. This is called neural plasticity . Dr. Megan Johnson, audiologist and owner of Johnson Audiology explains, “Neural plasticity is going gangbusters in a child’s brain as the child develops and matures into adulthood. Based on years of brain research, we also know that the adult brain is far from being fixed. It, too, changes and adapts when you learn new information or skills or as a response to stress, hormonal fluctuations, drug interactions, injury, and much more.” Dr. Johnson also relates that “your brain displays neuroplasticity when you experience hearing loss.” By measuring brain waves using an electroencephalograph, or EEG, scientists have studied how the brain of a person with hearing loss functions compared to a person with normal hearing. The results are both fascinating and sobering as studies reveal that, in those with hearing loss, the portion of the brain devoted to hearing becomes reorganized. This can be true even with early-stage, mild hearing loss, and the process happens quickly, often in months rather than years. The Hearing Center of Your Brain and Beyond What is actually happening when this takes place? Your brain has a right and a left hemisphere and six major lobes. Think of your frontal lobe as your brain’s boss, where executive functions like decision making, emotion and impulse control, and planning occur. Your temporal lobe, which contains the auditory cortex, is doing the heavy lifting when it comes to interpreting sounds and assigning those sounds meaning. The temporal lobe processes speech and language, and it is where initial learning of new information takes places, which is the first step for logging that information into memory. Dr. Johnson goes on to relate, “When the delicate infrastructure of your ear has become damaged through noise exposure, infection, etc. leading to hearing loss, your auditory cortex cries out to your frontal lobe, saying ‘Help! Help! I’m not receiving any sound to process, so I feel lost.’ The frontal lobe ‘boss’ jumps to attention, and your occipital lobe, responsible for processing vision and touch, takes over the areas in which hearing is normally processed. In other words, your other senses seek to compensate for the deficit due to the loss of your sense of hearing.” Amazing, right? So, where’s the rub? Picture a car assembly line; each worker has an assigned task. One day, the worker who installs the windshields is absent, and the worker who attaches the rearview mirrors is assigned double duty, and a duty that was not part of job training. It is easy to see how the worker left juggling both jobs is compromised, and a car might slip through minus a rear view mirror. Similarly, the areas of your brain that are being taxed to make up for a lack of hearing are overloaded and less able to do their assigned responsibilities. “This explains why so many of my patients with hearing loss relate feeling exhausted and frustrated after a big family gathering—where multiple talkers and sounds must be interpreted—rather than happy and invigorated by the experience. We call this listening fatigue ,” states Dr. Johnson. Additionally, when left untreated long enough, researchers point to the brain’s reorganization due to hearing loss as a significant correlation with dementia. Hearing Technology and Your Brain “But here's the great news!” Dr. Johnson says. When a person is fit with hearing aids or a cochlear implant and sound is restored, the brain has the ability to adjust back—partially or completely—to proper function. How swiftly that happens often depends on how long the hearing loss went untreated and is why she encourages patients to treat hearing loss sooner rather than later. “Here is what I tell patients who are downplaying the importance of hearing: If you won’t treat your hearing loss for the sake of your ears, do it for your brain!”

Move from the Gunbarrel Road office to a new and larger office will allow Johnson Audiology to help even more people in the Chattanooga region

By Jan Hollingsworth • 09 Jan, 2024
Johnson Audiology is pleased to announce that the practice will be moving one of its Chattanooga area offices from its current location on Gunbarrel Road to a new location at 6830 Lee Highway. The move will take place January 15. “We are extremely excited to be re-locating to a much larger space later this month,” Dr. Megan Johnson, founder and owner of the award-winning practice, says. “About a year ago, we realized that we needed more room to meet the needs of our growing patient base so we could help even more people with hearing loss. We sought a place that would allow us to stay in the East Brainerd/Hamilton Place area so that the office would still be conveniently located for patients. Our Hixson office will remain at 5617 Highway 153, Suite 203 and is also being upgraded with a second sound booth and beautiful new decor. These two strategically located offices mean that we can continue to serve patients who live east and west of the Tennessee River.” Dr. Johnson says that when she identified the building on Lee Highway, she knew it was an ideal site for this next growth leap. “Our company culture is anchored on the premise of always offering an exceptional patient experience,” she says. “Thanks to our wonderful family of Johnson Audiology patients, we have outgrown our current office and have found the perfect location for offering the best care to even more of our Chattanooga neighbors.” The new location offers many positive features that will benefit patients: The office is conveniently located off Lee Highway in the area between Shallowford Road and Hickory Valley Road, directly behind Dr. Keith B. Dressler’s orthodontic practice. It is a stand-alone office that is not shared with any other businesses. The building is more than 4,000 square feet, which is double the space of the current office on Gunbarrel Road. The added square footage will accommodate a spacious patient welcome and reception area, three sound booths for hearing testing, and a private area for patient check-out. The building has exam rooms for four full time audiologists and an audiology assistant, a large front desk area, and a sizeable lab for hearing aid maintenance and repair. The office has ample space for the practice’s growing Cochlear Implant (CI) Program with a dedicated sound booth and exam area just for CI patients. The building design allows for easy circular patient flow throughout the office. The building has a dedicated, 20-space parking lot just for Johnson Audiology patients and additional parking for Johnson Audiology staff. Dr. Johnson mentions that the building was a non-medical office previously, so updates were needed to bring it up to par for a bustling hearing health care clinic. It currently is being remodeled, and the parking lot resurfaced. “We have plans to transition to the new building by January 15 with some final touches to the office’s aesthetics continuing through the spring,” she says.  Dr. Johnson wishes to assure folks that measures are in place to alleviate disruption to the service patients receive during this time and thanks patients in advance for their continued support and understanding during the transition. “The new office is going to be incredible!” she says. Initial correspondence has been delivered to patients about the move. Dr. Johnson says, “Patients who have appointments scheduled in early January or those who need walk-in service for hearing aid maintenance and supplies from now until January 15 should continue visiting the Gunbarrel Road location.” Dr. Johnson says, “In February, we will invite our friends and neighbors in the Chattanooga community to an open house celebration, where we will do an official reveal of the new space!” Johnson Audiology has been faithfully serving the citizens of Chattanooga since the practice opened its doors on October 1, 2009. “As we prepare to celebrate our 15th anniversary this year, the new office location on Lee Highway and the upgrades to the Hixson office are evidence of our commitment to patients.” Dr. Johnson goes on to say, “Chattanoogans have named Johnson Audiology Best of the Best in the category of Favorite Audiologist and Hearing Aid Clinic for 11 years straight. And they consistently name Johnson Audiology in the top three in the category of Best Customer Service among all Chattanooga businesses. We seek to live up to those accolades daily!” Dr. Johnson concludes, “One of our patients, Mr. Van Tenpenny, recently had this to say about us: ‘My visit to Johnson Audiology has been life changing! After decades of hearing loss, I am able to hear normal conversations in any environment.’ It is our highest ideal to be here for Mr. Tenpenny and the thousands of other patients like him who prioritize their hearing for the best quality of life.” Do you want to get on the road to healthy hearing? Johnson Audiology is currently accepting new patients at all locations. Call today to schedule an appointment or book online at www.johnsonaudiology.com/schedule.
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