An audiogram is a graph that maps your hearing ability across different pitches and volumes. It’s the standard result you get from a hearing test, and it shows the quietest sounds you can detect at each frequency tested. Each ear gets its own set of results, plotted as points on the graph, giving your audiologist a detailed picture of exactly where your hearing is strong and where it may have shifted.
How the Graph Is Laid Out
An audiogram has two axes. The horizontal axis (left to right) represents pitch, measured in hertz (Hz). Low-pitched sounds like a lawnmower hum sit on the left side, while high-pitched sounds like a bird chirping sit on the right. Most clinical audiograms test at specific pitch points: 250, 500, 1000, 2000, 4000, and 8000 Hz.
The vertical axis represents volume, measured in decibels hearing level (dB HL). Here’s where audiograms can feel counterintuitive: the scale is inverted. Zero sits at the top, and the numbers increase going down. So a mark near the top of the graph means you heard a very quiet sound, which is good. A mark further down means the sound had to be turned up louder before you could detect it, which indicates some degree of hearing loss at that pitch.
What the Symbols Mean
You’ll notice different symbols for each ear. The right ear is typically marked with an “O” (often in red), and the left ear with an “X” (often in blue). These represent air conduction testing, which is the part of the test where you wear headphones and listen for tones. The symbols are connected by lines to show your hearing pattern across all the pitches tested.
Some audiograms also include a second set of symbols for bone conduction testing. During this part, a small vibrating device is placed behind your ear on the bone. It sends sound vibrations directly to your inner ear, bypassing the ear canal and eardrum entirely. Comparing the two sets of results tells your audiologist something important: whether a hearing problem is coming from the outer/middle ear, the inner ear, or both.
What Happens During the Test
The test itself is straightforward. You sit in a soundproof booth wearing headphones, and the audiologist plays a series of tones at different pitches. Each tone starts quiet and gets gradually louder in small steps (5 decibels at a time) until you can hear it. When you hear the sound, you press a button or raise your hand. If you respond, the volume drops back down 10 decibels and the process starts again from that lower point. Your “threshold” for each pitch is the quietest level where you respond at least half the time across several attempts. The whole process typically takes 15 to 30 minutes for both ears.
Degrees of Hearing Loss
The American Speech-Language-Hearing Association classifies hearing based on where your thresholds fall on the decibel scale:
- Normal: -10 to 15 dB HL
- Slight: 16 to 25 dB HL
- Mild: 26 to 40 dB HL
- Moderate: 41 to 55 dB HL
- Moderately severe: 56 to 70 dB HL
- Severe: 71 to 90 dB HL
- Profound: 91+ dB HL
These categories apply at each frequency individually. You might have normal hearing in the low pitches and mild loss in the high pitches, which is actually one of the most common patterns, especially with age-related hearing change. The degree of loss can also differ between your two ears.
Three Types of Hearing Loss on an Audiogram
The relationship between your air conduction results (headphone test) and bone conduction results (vibrating device test) reveals which type of hearing loss you have.
Sensorineural hearing loss shows up when both air and bone conduction thresholds are equally reduced. This means the inner ear or the hearing nerve itself isn’t picking up sound normally. The two lines on your audiogram sit close together, but both are shifted downward from the normal range. Age-related hearing loss and noise-induced damage typically show this pattern, often worse in the higher pitches.
Conductive hearing loss shows a gap between the two test results. Your bone conduction scores look normal (near the top of the graph), but your air conduction scores are pushed down. This gap, called an air-bone gap, means sound is having trouble getting through the outer or middle ear. Causes include fluid behind the eardrum, earwax blockage, or problems with the tiny bones in the middle ear. Conductive losses are often treatable with medical or surgical intervention.
Mixed hearing loss is a combination of both. The bone conduction line is below normal, and the air conduction line is even further below that, creating a gap on top of an underlying inner-ear problem.
The Speech Banana
One of the most practical features of an audiogram is something called the “speech banana.” It’s a banana-shaped zone drawn on the graph that represents where the sounds of spoken language fall. Speech sounds span roughly 250 to 8000 Hz in pitch and 10 to 60 dB HL in volume. Different speech sounds land in different spots within this zone. Low-pitched vowel sounds like “u” and “o” cluster toward the left, while high-pitched consonants like “s,” “f,” “sh,” and “th” sit further to the right.
This is why the speech banana matters so much practically. If your hearing thresholds dip below the banana at certain frequencies, those specific speech sounds become harder to hear. A person with high-frequency hearing loss, for instance, might hear that someone is talking but struggle to distinguish between “s” and “f” or miss the “th” sound entirely. Words start to sound mumbled, not because the speaker is unclear, but because certain consonants have dropped below the listener’s hearing threshold. Looking at where your results fall relative to the speech banana gives you and your audiologist a quick sense of how your hearing loss is affecting everyday conversation.
Common Audiogram Patterns
Certain shapes on the audiogram point toward specific causes. A “sloping” pattern, where hearing is relatively normal in the low frequencies and progressively worse in the high frequencies, is the hallmark of age-related hearing loss and long-term noise exposure. A “flat” pattern, where thresholds are roughly equal across all frequencies, can suggest certain middle-ear conditions or genetic causes.
A “cookie bite” or “U-shaped” pattern shows loss concentrated in the middle frequencies with better hearing on both ends. This pattern is less common and often has a genetic basis. A “reverse slope” pattern, worse in the low frequencies and better in the highs, is rare and can be associated with conditions like Meniere’s disease. A “notch” pattern, with a sharp dip at 4000 Hz and recovery at 8000 Hz, is a classic sign of noise-induced hearing damage.
Your audiologist reads these patterns alongside your medical history to figure out the likely cause and the best path forward. The audiogram on its own doesn’t diagnose a specific condition, but the shape of your hearing loss narrows the possibilities considerably and determines whether hearing aids, medical treatment, or further testing is the right next step.