How to read an audiogram.

If you have ever held a sheet of paper handed to you after a hearing test and wondered what the dots, X's, and O's meant, the chart is an audiogram. It is a deliberately simple graph of one measurement at a time: how much volume each ear needs at each pitch before the test taker can just barely detect the sound. Reading it is straightforward once you understand the convention.

What an audiogram measures

A pure-tone audiogram measures your hearing thresholds — the softest sound your ear can detect at a given pitch — for each ear separately. The test is administered by an audiologist in a sound-treated booth using calibrated headphones (and, for bone-conduction testing, a small vibrator placed behind the ear). The audiologist plays brief tones at successive volumes and asks you to indicate whenever you can just barely hear one. The softest volume at which you reliably detect each pitch is recorded as that threshold.

The result is two curves — one per ear — plotted on the audiogram chart.

The two axes

Frequency (x-axis). Frequencies are measured in hertz (Hz). Standard audiograms test from 250 Hz on the left to 8,000 Hz on the right, plotted at one-octave (sometimes half-octave) intervals: 250, 500, 1000, 2000, 4000, 8000 Hz, with optional 125, 750, 1500, 3000, and 6000 Hz. Low pitches (a tuba, a low male voice) live on the left; high pitches (a violin's top notes, consonants like "s," "f," "th") live on the right.

Hearing level (y-axis). Hearing level is measured in dB HL — decibels Hearing Level — a unit calibrated to the average softest sound a young, healthy adult can detect at each frequency. 0 dB HL is not silence; it is the threshold for normal young-adult hearing. The y-axis is inverted: 0 dB HL (best) is at the top, 110+ dB HL (worst) is at the bottom. Lower on the chart means worse hearing.

The standard ASHA symbols

The American Speech-Language-Hearing Association publishes audiometric symbol conventions (ASHA Guidelines for Audiometric Symbols). When color is available, red indicates the right ear and blue indicates the left ear. In black and white, the symbol shape carries the same meaning.

Many clinics also connect a wearer's air-conduction thresholds for one ear with a solid line (right ear) and a dashed line (left ear) to make the pattern across frequencies easier to see at a glance. That is a convenience, not a measurement.

Severity: how to read where the symbols sit

Once you can place a symbol at a frequency and a dB HL value, the next question is what that value means clinically. ASHA's classification divides adult hearing levels into bands:

Severity is not necessarily the same at every frequency. The pattern matters as much as any single number.

Configuration: the shape of the curve

The shape of an audiogram across frequencies — what audiologists call the configuration — is often more informative than the simple severity at any single pitch (ASHA, Type, Degree, and Configuration of Hearing Loss). Common patterns:

• Sloping — thresholds get worse as frequency increases. The classic age-related (presbycusis) pattern; the example audiogram above is sloping.
• Steeply sloping ("ski-slope") — near-normal at low frequencies, abruptly worse at high frequencies. Often associated with noise exposure.
• Flat — similar threshold across all frequencies. Less common in age-related loss.
• Rising — worse at low frequencies, better at high. Can occur in certain middle-ear and inner-ear conditions.
• Cookie-bite (U-shaped) — worse in the middle frequencies, better at the extremes. Often genetic.
• Notched — a localized dip, usually at 4,000 Hz, typically associated with noise-induced hearing loss.

Type: air vs bone conduction

When the audiogram includes both air-conduction (O, ×) and bone-conduction (<, >) symbols, the relationship between them tells the audiologist what type of hearing loss is present:

• Sensorineural hearing loss: Both air- and bone-conduction thresholds are abnormal, and they overlap. The problem is in the inner ear or auditory nerve. This is the type hearing aids are designed to compensate for.
• Conductive hearing loss: Bone-conduction thresholds are normal, but air-conduction thresholds are abnormal. There is a "gap" between the two. The problem is in the outer or middle ear (earwax, fluid, eardrum, ossicles) and is often medically treatable.
• Mixed hearing loss: Both air and bone are abnormal, but there is still a gap between them. Both an inner-ear component and an outer/middle-ear component are present.

If you have any air-bone gap on your audiogram, that is a reason for a clinician's evaluation, not just a consumer hearing aid.

How to read your own audiogram in 30 seconds

1. Locate the legend or symbol key on the page.
2. Find the O's and X's (or the right/left air-conduction lines).
3. Trace each from left to right and ask: does the curve sit in the normal band the whole way, or does it drop down at the higher frequencies?
4. If it drops, note where — the drop typically starts somewhere between 1,000 and 4,000 Hz in age-related loss.
5. At each frequency, place the symbol against the severity band on the right of the chart (normal / mild / moderate / etc.) to estimate the degree of loss at that frequency.
6. Check whether the two ears are similar or asymmetric. Significant asymmetry is a reason for clinical evaluation.
7. If bone-conduction symbols (<, >) are present, check whether they overlap with the air-conduction symbols or sit higher (closer to 0 dB HL).

What an audiogram does not tell you

An audiogram is a precise instrument, but it has limits worth understanding:

• It does not diagnose the cause of hearing loss. Age-related loss, noise-induced loss, ototoxic damage, and genetic loss can all produce similar audiogram patterns. The audiogram tells you the degree, configuration, and type; the cause comes from history, examination, and sometimes imaging.
• It does not measure speech understanding directly. Two adults with similar audiograms can differ substantially in real-world speech-in-noise performance. Speech-in-noise testing is a separate measurement.
• It does not measure loudness tolerance. The threshold is the softest level you can detect, not the loudest you find comfortable. Some hearing aid wearers have a narrow dynamic range between threshold and discomfort.
• It does not tell you which device to buy. A pure-tone audiogram is a starting point. Real-world device performance depends on fit, signal processing, and environment.

What to ask after a hearing test

If you have just been handed an audiogram and want to leave the appointment understanding it, ask the audiologist:

1. What is the degree of my hearing loss (in plain words: normal, mild, moderate…)?
2. What is the configuration (sloping, flat, notched…)?
3. Is the loss sensorineural, conductive, or mixed?
4. Is it symmetric between ears?
5. Is there anything on the audiogram that warrants a referral to an ENT or further imaging?
6. If hearing aids are recommended, are OTC devices appropriate for my audiogram, or do I need prescription?

The bottom line

An audiogram is a graph of how soft a sound has to be before you can detect it at each pitch, for each ear, plotted with frequency across the x-axis and inverted hearing level on the y-axis. The standard ASHA symbols (O for right, × for left, < and > for bone conduction) and the ASHA severity bands (normal through profound) are all you need to read the page. Once you can see whether the curves sit in the normal band, slope down at higher frequencies, or differ between ears, you have the substantive information clinicians use to recommend a fitting path.