How to Read an Audiogram: Symbols, Hearing Loss Levels, and What Your Results Mean
After a hearing test, your audiologist hands you a graph with Xs, Os, and lines that slope downward. That graph is your audiogram, and it shows how loud different pitches need to be before you can hear them. Understanding the axes, symbols, and degree ranges helps you interpret your results and judge whether OTC or prescription hearing aids fit your loss.
Key takeaways
- An audiogram is a graph of how loud tones must be before you hear them. Frequency (pitch) runs left to right, loudness (dB HL) runs top to bottom. Soft sounds at the top, loud sounds at the bottom.
- O and X are the most common symbols. Red O typically represents the right ear, blue X the left ear (ASHA convention). Brackets show bone conduction results, arrows show no response at the audiometer's maximum output.
- Hearing loss degrees are defined by dB HL ranges. ASHA categorizes normal as -10 to 15 dB HL, mild as 26 to 40 dB HL, moderate as 41 to 55 dB HL, and so on up to profound at 91+ dB HL (Clark 1981).
- The speech banana shows where conversational speech falls. Thresholds that fall below the speech banana mean speech clarity is compromised even when volume is adequate.
- Conductive, sensorineural, and mixed loss require bone conduction testing to distinguish. Air-bone gaps indicate conductive loss (often treatable). Matching air and bone thresholds indicate sensorineural loss (permanent).
People search for how to read an audiogram when they have just had a hearing test and want to interpret the graph themselves before or after the audiologist explains it. The audiogram is not a diagnosis on its own, but it is the foundation of every hearing aid fitting and the clearest way to track change over time. This page explains the axes, the symbols, the ASHA degree-of-hearing-loss ranges, the speech banana, common configuration patterns, and what your results mean for choosing OTC or prescription hearing aids.
What is an audiogram? The direct answer
What is an audiogram? An audiogram is a graph of the results of a pure-tone hearing test. It shows how loud a sound needs to be at different frequencies (pitches) for you to hear it. According to the American Speech-Language-Hearing Association (ASHA), the audiogram provides information about the type, degree (severity), and configuration (shape) of your hearing loss. Frequency in Hertz (Hz) runs from left to right on the horizontal axis, with low pitches on the left and high pitches on the right. Loudness in decibels hearing level (dB HL) runs from top to bottom on the vertical axis, with soft sounds (0 dB) at the top and loud sounds (120 dB) at the bottom.
During a hearing test, you listen to a series of tones through headphones and signal when you hear them (usually by pressing a button or raising your hand). The audiologist records the softest level at which you can hear each tone and plots those thresholds on the graph. The audiogram shows your hearing sensitivity at each frequency tested, typically from 125 Hz to 8000 Hz.
An audiogram is one part of a complete hearing evaluation. It shows how much hearing loss you have and where, but your audiologist interprets the results in the context of your history, symptoms, and other tests (such as speech recognition in noise and middle ear function). Do not self-diagnose from the graph alone.
The two axes: frequency (Hz) and loudness (dB HL)
Frequency: pitch from low to high
The horizontal axis (left to right) shows frequency in Hertz (Hz), which is the pitch or tone of a sound. Low pitches are on the left, high pitches on the right. According to ASHA audiogram guidance, the tested range typically includes frequencies from 125 Hz to 8000 Hz. A note from a tuba or the "oo" sound in the word "who" is a low-frequency sound. A bird chirping or the "s" sound in the word "sun" is a high-frequency sound.
The frequency axis is logarithmic, meaning each doubling of frequency (an octave) occupies the same horizontal distance on the graph. The standard test frequencies are 250, 500, 1000, 2000, 4000, and 8000 Hz, with optional testing at 125, 3000, 6000, and frequencies above 8000 Hz if clinically indicated. Interoctave frequencies like 750, 1500, 3000, and 6000 Hz are sometimes plotted with dashed grid lines.
Loudness: decibels hearing level (dB HL)
The vertical axis (top to bottom) shows loudness in decibels hearing level (dB HL). ASHA specifies that soft sounds (0 dB) are at the top of the chart and loud sounds (120 dB) are at the bottom. The 0 dB line represents the average threshold for young adults with normal hearing at each frequency, not absolute silence. Negative dB HL values (such as -10 dB) indicate better-than-average hearing sensitivity. Most audiogram forms show a range from -10 dB to 120 dB HL, with grid lines at 10 dB intervals.
Decibels are a logarithmic scale, so a 10 dB increase represents a sound that is roughly twice as loud perceptually. A threshold of 40 dB HL means that a tone had to be 40 decibels louder than the reference level before you could detect it.
Many first-time readers expect better hearing to be at the top of the graph and worse hearing at the bottom, which is correct. But the thresholds (the symbols) go down the page as hearing gets worse because they represent how loud the tone had to be. The farther down the graph, the louder the sound needed to be, which means more hearing loss.
Audiogram symbols: O, X, brackets, and arrows
ASHA published Guidelines for Audiometric Symbols in 1990 (adopted by the ASHA Legislative Council in November 1989) to standardize the way audiologists record pure-tone test results. The symbols distinguish left ear from right ear, air conduction from bone conduction, masked from unmasked conditions, and response from no response. Here are the most common symbols you will see on your audiogram:
| Symbol | Meaning | What it shows |
|---|---|---|
| Red O (circle) | Right ear, unmasked air conduction | How loud a tone had to be for the right ear to detect it, delivered through headphones |
| Blue X | Left ear, unmasked air conduction | How loud a tone had to be for the left ear to detect it, delivered through headphones |
| Red [ (bracket open right) | Right ear, masked bone conduction | Right ear inner ear threshold, measured with vibration behind the ear while the left ear is masked |
| Blue ] (bracket open left) | Left ear, masked bone conduction | Left ear inner ear threshold, measured with vibration behind the ear while the right ear is masked |
| Down arrow attached to symbol | No response at maximum output | The tone was played at the audiometer's loudest level and you still did not hear it |
| ^ (caret or upside-down V) | Unmasked bone conduction, placement unspecified | Inner ear threshold, no masking, cannot assign to either ear (used when hearing loss is symmetrical) |
Red O and blue X are the symbols you will see on almost every audiogram for air conduction thresholds (sound delivered through headphones or insert earphones). ASHA guidance notes that the farther down the graph these marks appear, the louder the tone had to be before you could hear it, which represents the degree of your hearing loss.
Bone conduction symbols (brackets) show the results of testing with a vibrating device placed behind your ear. Bone conduction bypasses the outer and middle ear and tests the inner ear (cochlea) directly. This distinction is essential for identifying the type of hearing loss (conductive, sensorineural, or mixed), which we cover below.
No-response arrows indicate that the audiometer could not produce a tone loud enough for you to hear at that frequency. This is common in profound hearing loss.
Hearing loss levels by dB HL: the ASHA degree table
The degree of hearing loss describes the severity of your loss based on how loud sounds need to be for you to hear them. ASHA categorizes hearing loss using the following ranges, which are sourced from Clark, J. G. (1981), "Uses and abuses of hearing loss classification," published in Asha, 23, 493-500:
| Degree | Threshold range (dB HL) | What you might notice |
|---|---|---|
| Normal | -10 to 15 | No difficulty hearing soft sounds or following conversation in noise |
| Slight | 16 to 25 | Soft speech or whispers may be missed; background noise is slightly harder |
| Mild | 26 to 40 | Soft speech and noisy rooms are challenging; quiet conversation is usually fine |
| Moderate | 41 to 55 | Normal-volume conversation takes effort even in quiet; group settings are difficult |
| Moderately severe | 56 to 70 | Speech must be loud to be heard; amplification is usually essential |
| Severe | 71 to 90 | Only shouted or amplified speech is audible |
| Profound | 91+ | Little to no benefit from sound without powerful amplification or a cochlear implant |
ASHA notes that not all professionals agree on the cutoff for normal hearing. Although the table above specifies 15 dB HL as the upper limit for normal, some professionals use 20 dB HL or 25 dB HL. This variation reflects ongoing debate in the audiology community about what constitutes clinically significant hearing loss.
Your audiologist calculates your pure-tone average (PTA) by averaging your thresholds at the speech-important frequencies, typically 500, 1000, and 2000 Hz (sometimes 1000, 2000, and 4000 Hz for a high-frequency PTA). The PTA gives a single number that summarizes the degree of your hearing loss for speech, which is the most functionally relevant measure.
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The speech banana: where conversational speech falls
On many audiograms, you will see a banana-shaped region overlaid on the graph. ASHA audiogram guidance explains that this "speech banana" shows where the sounds in human speech are located. The sounds in this area typically range from 250 Hz to 4000 Hz in frequency (pitch) and from 20 dB to 60 dB in loudness. Vowels (like "ah" and "oo") are lower in pitch and louder, so they appear toward the bottom left of the banana. Consonants (like "s," "f," "th," and "t") are higher in pitch and softer, so they appear toward the top right.
ASHA notes that the speech banana pictured on most English-language audiogram forms applies specifically to English. Different languages have different speech bananas because the phonemes and pitch patterns vary.
If your hearing thresholds (the O and X symbols) fall within or above the speech banana, you can usually hear conversational speech without amplification, although understanding in noise may still be difficult. If your thresholds fall below the speech banana, especially at the high frequencies where consonants live, speech clarity is compromised even when the volume is adequate. You might hear that someone is talking but cannot distinguish the words.
Age-related and noise-induced hearing loss typically affect high frequencies first. High frequencies carry consonants, which distinguish words like "cat" from "cap" or "sit" from "sip." When you lose high-frequency hearing, vowels (which are louder and lower-pitched) remain audible, so speech sounds loud enough but unclear. This is why people with early hearing loss often say "I can hear, I just cannot understand."
Common audiogram configuration patterns
ASHA audiogram guidance describes configuration as the shape of your hearing loss on the graph. The pattern of which frequencies are affected tells your audiologist important information about the likely cause of the loss and what to expect with amplification. Here are the most common patterns:
High-frequency sloping loss
This is the most common pattern in age-related and noise-induced hearing loss. Thresholds are normal or near-normal at low frequencies (250 to 1000 Hz) and drop progressively at higher frequencies (2000 Hz and above). On the graph, the symbols slope downward from left to right. People with this pattern often say they hear fine in quiet one-on-one conversation but struggle in restaurants or groups, because high-frequency consonants are lost while low-frequency vowels remain audible.
Flat hearing loss
Thresholds are similar across all frequencies, forming a horizontal line on the audiogram. This pattern appears in some conductive losses (such as middle ear fluid or otosclerosis) and in certain sensorineural conditions. Amplification tends to work well for flat losses because the same amount of gain is needed across the frequency range.
Low-frequency hearing loss
Less common than high-frequency loss, but seen in Meniere's disease and some genetic conditions. Thresholds are worse at low frequencies and better at high frequencies, forming an upward slope from left to right. People with this pattern may hear high-pitched sounds (birds, alarms) clearly but struggle with low-pitched voices or rumbling sounds.
Cookie-bite (mid-frequency) loss
Thresholds are normal or near-normal at low and high frequencies but drop in the middle frequencies (around 1000 to 2000 Hz), forming a U-shape or notch on the graph. This pattern is often hereditary.
Unilateral (one-sided) loss
One ear has normal or near-normal hearing (O or X symbols near the top of the graph) and the other ear has significant loss (symbols much farther down). Unilateral hearing loss can result from sudden sensorineural hearing loss, acoustic neuroma, head injury, or Meniere's disease. ASHA guidance on types of hearing loss notes that unilateral loss affects sound localization (knowing where a sound is coming from) and understanding speech in noisy environments.
Asymmetrical hearing loss
Both ears have hearing loss, but one ear is noticeably worse than the other. ASHA audiogram guidance specifies that if the hearing loss is similar in both ears, it is symmetrical; if it is different in each ear, the hearing loss is asymmetrical. Asymmetrical loss requires medical evaluation to rule out treatable or structural causes before amplification.
Air vs bone conduction: conductive, sensorineural, and mixed hearing loss
Understanding whether your hearing loss is conductive, sensorineural, or mixed requires bone conduction testing, which is why app-based hearing checks and online tests cannot give you a complete diagnosis. ASHA describes three main types of hearing loss based on which part of the hearing system is affected:
Conductive hearing loss
Conductive hearing loss happens when sounds cannot move through the outer and middle ear to get to the inner ear. According to ASHA types of hearing loss guidance, conductive loss can be caused by fluid in the middle ear from colds or allergies, ear infections (otitis media), a hole in the eardrum, earwax blocking the ear canal, infection in the ear canal (otitis externa or swimmer's ear), or a problem with how the outer or middle ear is formed. In many cases, medication or surgery can correct conductive hearing loss.
On an audiogram, conductive loss shows up as an air-bone gap. Air conduction thresholds (O and X symbols) are worse (farther down the graph) than bone conduction thresholds (bracket symbols). The bracket symbols, which represent the inner ear's response to vibration, are near the top of the graph (normal or near-normal), while the O and X symbols are farther down. The gap between them, measured in dB, indicates how much of the loss is due to a problem in the outer or middle ear rather than the inner ear.
Sensorineural hearing loss (SNHL)
Sensorineural hearing loss happens when the inner ear (cochlea) or the nerve pathways connecting the inner ear to the brain are damaged. ASHA notes that this is the most common type of permanent hearing loss. Unlike conductive hearing loss, SNHL usually cannot be corrected with medicine or surgery. Hearing aids or other assistive listening technology may be recommended to help with SNHL.
SNHL can be caused by illnesses, drugs that are toxic to hearing (ototoxic medications such as certain antibiotics or chemotherapy agents), hearing loss that runs in the family (genetic factors), aging (presbycusis), head injury, a problem in the way the inner ear is formed, or exposure to loud sounds (noise-induced hearing loss).
On an audiogram, sensorineural loss shows air conduction and bone conduction thresholds at the same level or within a few dB of each other. The O and X symbols and the bracket symbols are all near the same place on the graph. No air-bone gap means the outer and middle ear are functioning normally, and the loss is in the inner ear or auditory nerve.
Mixed hearing loss
Mixed hearing loss is a combination of both conductive and sensorineural hearing loss. ASHA explains that this means there are problems in the outer or middle ear and the inner ear or auditory nerve. For example, someone who works in a noisy environment (causing sensorineural loss) and also has fluid buildup in the middle ear (causing conductive loss) may have a mixed hearing loss and experience more severe hearing difficulties than if they had only one type of hearing loss.
On an audiogram, mixed loss shows an air-bone gap (indicating conductive loss) and bone conduction thresholds that are not normal (indicating sensorineural loss). Both the air conduction symbols and the bone conduction symbols are below the normal range, but the air conduction symbols are farther down than the bone conduction symbols.
What your audiogram means for choosing hearing aids
Your audiogram is the starting point for every hearing aid decision. It tells your audiologist (or tells you, if you are considering OTC devices) whether amplification is appropriate, what degree of loss you have, whether the loss is conductive or sensorineural, and what style and power level of hearing aid will fit your needs. Here is how to interpret your results for the OTC vs prescription decision:
Mild to moderate sensorineural loss: OTC may be appropriate
If your audiogram shows thresholds in the mild to moderate range (roughly 26 to 55 dB HL at speech frequencies), the loss is sensorineural (air and bone conduction thresholds match), the loss is similar in both ears, it came on gradually, and you have no red-flag symptoms (sudden loss, one-sided loss, pain, drainage, dizziness), OTC hearing aids may be appropriate. According to the FDA OTC rule (effective October 17, 2022), OTC hearing aids are for adults 18 years of age and older with perceived mild to moderate hearing loss. OTC devices allow you to customize the settings yourself through controls, tests, or smartphone apps, without a professional fitting.
For details on the OTC vs prescription decision tree, see our OTC vs prescription hearing aids guide.
Moderately severe to profound loss: prescription required
If your audiogram shows thresholds in the moderately severe, severe, or profound range (56 dB HL or greater at speech frequencies), OTC hearing aids are not appropriate. FDA guidance notes that OTC devices are limited in their maximum output and may not provide adequate benefit for more severe hearing losses. You need prescription hearing aids, which are fit and programmed by a licensed hearing care professional (audiologist or hearing aid dispenser) and verified in your ear with real-ear measurement.
For more on what happens at a hearing aid fitting appointment and why real-ear verification matters, see our hearing aid fitting guide.
Conductive or mixed loss: see a specialist first
If your audiogram shows an air-bone gap (air conduction worse than bone conduction by 10 dB or more), you have conductive or mixed hearing loss. Do not buy any hearing aid, OTC or prescription, until you have seen an ear, nose, and throat (ENT) physician or an audiologist for a full evaluation. Conductive losses are often treatable with medication or surgery, and amplifying through a conductive problem can mask a fixable cause or make the problem worse.
For understanding when to see an ENT vs an audiologist, see our audiologist vs ENT comparison.
Red-flag patterns: urgent evaluation
If your audiogram shows sudden hearing loss (a significant drop within the past 90 days), one-sided loss (one ear much worse than the other), or if you have ear pain, drainage, dizziness, or hearing loss after a head injury, do not buy hearing aids. See a physician or audiologist immediately. These are the FDA's red-flag conditions, and they require medical evaluation before any amplification.
For detailed guidance on sudden hearing loss, see our sudden hearing loss emergency guide.
Questions to ask your audiologist about your audiogram
After your hearing test, your audiologist will explain your results. Here are the questions to ask to make sure you understand your audiogram and what it means for treatment:
- Can I have a copy of my audiogram? You should always get a copy. You will need it if you get a second opinion, if you move and see a new provider, or if you want to compare results over time. Most clinics provide a paper copy or a digital file.
- What is my pure-tone average (PTA)? This is the average of your thresholds at the speech-important frequencies (usually 500, 1000, and 2000 Hz). It gives you a single number that summarizes the degree of your hearing loss.
- Is my loss conductive, sensorineural, or mixed? The answer tells you whether your loss might be treatable with medical or surgical intervention or whether amplification is the appropriate path.
- Is my hearing loss symmetrical or asymmetrical? If one ear is significantly worse than the other, ask why. Asymmetrical loss often requires further testing (such as an MRI) to rule out structural causes.
- What does the configuration (shape) of my loss mean? Ask your audiologist to explain why your loss slopes at high frequencies, why one frequency range is worse than others, or what the pattern suggests about the cause and prognosis.
- Do I need hearing aids in both ears? If you have hearing loss in both ears, your audiologist will almost always recommend binaural (two-device) fitting because it improves sound localization, speech understanding in noise, and overall satisfaction compared to wearing one device.
- What degree of hearing loss do I have, and how might it change over time? Ask whether your loss is mild, moderate, or severe, and whether it is expected to be stable or progressive. This helps you plan for follow-up testing and future device needs.
- Am I a candidate for OTC hearing aids, or do I need prescription devices? Your audiologist can tell you whether your loss falls within the mild to moderate range and whether any red flags rule OTC out.
- When should I come back for a retest? Ask how often you should have your hearing checked. Annual testing is common for adults over 50, or sooner if you notice a change.
If your audiogram shows normal hearing or only slight loss, still keep the copy. Comparing your baseline to results in five or ten years is the best way to detect early change. Many people wish they had a baseline from their 40s or 50s when they see their audiologist in their 60s or 70s.
Frequently asked questions
What is a normal audiogram? +
A normal audiogram shows thresholds at -10 to 15 dB HL across all frequencies, according to the ASHA degree of hearing loss table (Clark 1981). Some professionals use 20 or 25 dB HL as the upper limit for normal. Normal hearing means you can detect soft sounds without difficulty and follow conversation in noisy rooms without consistent effort. If your thresholds fall below the normal range at any frequency, that indicates measurable hearing loss at those pitches.
What do the O and X mean on an audiogram? +
Red O typically represents the right ear, and blue X represents the left ear, according to ASHA audiogram guidance. Each symbol is plotted at the softest level you could hear a tone at a specific frequency. The farther down the graph the marks appear, the louder the tone had to be before you could hear it, which indicates greater hearing loss. This convention is nearly universal in audiology clinics.
What does 40 dB on a hearing test mean? +
A threshold of 40 dB HL at a given frequency means that a tone at that pitch had to be 40 decibels louder than the reference level (the average threshold for young adults with normal hearing) before you could detect it. According to the ASHA degree of hearing loss table, 40 dB HL falls at the upper edge of mild hearing loss (26 to 40 dB HL range). At this level, soft speech and noisy environments become challenging, but normal-volume conversation in quiet is usually manageable.
What are the levels of hearing loss on an audiogram? +
ASHA categorizes hearing loss by degree using the dB HL thresholds: Normal is -10 to 15 dB HL, Slight is 16 to 25 dB HL, Mild is 26 to 40 dB HL, Moderate is 41 to 55 dB HL, Moderately severe is 56 to 70 dB HL, Severe is 71 to 90 dB HL, and Profound is 91+ dB HL. These ranges are based on Clark (1981). The degree that describes your loss is typically based on the average of thresholds at speech-important frequencies (usually 500, 1000, and 2000 Hz), which your audiologist calculates as your pure-tone average.
What is the speech banana? +
The speech banana is a banana-shaped region on an audiogram that shows where the sounds of human speech typically fall. According to ASHA, speech sounds usually range from 250 to 4000 Hz in frequency and from 20 to 60 dB in loudness. If your hearing thresholds fall within or above the speech banana, you can usually hear conversational speech without amplification. If your thresholds fall below it, speech will be difficult to understand.
How can I tell conductive from sensorineural loss on an audiogram? +
The distinction requires bone conduction testing, which your audiologist performs with a vibrating device placed behind the ear. Bone conduction bypasses the outer and middle ear and tests the inner ear directly. If bone conduction thresholds (brackets on the audiogram) are better than air conduction thresholds (O and X symbols) by 10 dB or more at any frequency, that gap indicates conductive hearing loss (a problem in the outer or middle ear, often treatable). If air and bone conduction thresholds match, the loss is sensorineural (inner ear or nerve damage, permanent). If both patterns appear, the loss is mixed. This is why app-based hearing checks cannot give you a complete diagnosis.
Can I use my audiogram to buy OTC hearing aids? +
If your audiogram shows perceived mild to moderate hearing loss (thresholds roughly in the 26 to 55 dB HL range at speech frequencies), you are 18 or older, the loss is sensorineural and gradual, and you have no red-flag symptoms (sudden loss, one-sided loss, pain, drainage, dizziness), OTC hearing aids may be appropriate. The FDA OTC category (effective October 17, 2022) is for adults 18 and older with perceived mild to moderate hearing loss. If your loss is more severe, if you have an air-bone gap indicating conductive loss, or if any red flag applies, prescription hearing aids with professional fitting are the appropriate path. For the decision tree, see our OTC vs prescription hearing aids guide.
Sources and next reads
For more on the hearing aid selection process and understanding your hearing loss, see the following:
- How to choose hearing aids in 2026: the decision tree for first-time buyers, from audiogram to features to style to technology tier.
- 10 early signs of hearing loss: the symptoms that prompt most people to get a hearing test, and when to seek urgent care.
- Hearing aid fitting guide: what happens at the appointment where your hearing care professional programs devices to your audiogram and verifies the output with real-ear measurement.
- OTC vs prescription hearing aids: which category fits your loss, and the red flags that rule OTC out.
- Audiologist vs ENT: who to see for a hearing test, who to see for medical evaluation, and when you need both.
- Browse the hearing aid catalog: compare models by manufacturer with styles, fitting ranges, and features.
Primary sources
- American Speech-Language-Hearing Association, Audiograms and Hearing Loss Configuration. Accessed October 8, 2026.
- American Speech-Language-Hearing Association, Degree of Hearing Loss. Source: Clark, J. G. (1981). Uses and abuses of hearing loss classification. Asha, 23, 493-500. Accessed October 8, 2026.
- American Speech-Language-Hearing Association, Guidelines for Audiometric Symbols (adopted by ASHA Legislative Council November 1989, published 1990). Accessed October 8, 2026.
- American Speech-Language-Hearing Association, Types of Hearing Loss. Accessed October 8, 2026.
- U.S. Food and Drug Administration, OTC Hearing Aids: What You Should Know (content current as of May 3, 2023). Accessed October 8, 2026.