How to read an audiogram
An audiogram is a chart of the quietest sounds you can hear at each pitch. Pitch runs left to right (low to high), loudness runs top to bottom (quiet to loud), so the lower a point sits on the chart, the louder that pitch had to be before you heard it, and the worse your hearing there.
The two axes
- Across (frequency, in Hz): from low rumbles at 250 Hz on the left to high, thin sounds at 8,000 Hz on the right. Speech vowels live at the low end; consonants like s, f, th live at the high end.
- Down (hearing level, in dB HL): 0 dB HL at the top is the softest level a young healthy ear detects; each step down means the sound had to be louder for you. dB HL is "hearing level", calibrated against normal hearing, which is why 0 is normal rather than silence.
Why right is a red O and left is a blue X
Audiology has drawn it the same way for decades: the right ear is plotted as red circles (O), the left ear as blue crosses (X) for headphone (air-conduction) testing. Handy mnemonic: red–right–round. Two separate lines let you spot at a glance whether one ear is doing worse than the other, an asymmetry worth showing to a professional.
The degrees of hearing loss
Clinicians band thresholds into degrees. The commonly used scale:
| Threshold (dB HL) | Degree | In everyday terms |
|---|---|---|
| up to 25 | Normal | No practical difficulty |
| 26–40 | Mild | Soft speech and noisy rooms are hard |
| 41–55 | Moderate | Normal conversation is hard without help |
| 56–70 | Moderately severe | Loud speech needed |
| 71–90 | Severe | Only very loud sounds heard |
| over 90 | Profound | Mostly vibration and very loud sound |
Reading a real result
The most common adult pattern is a line that starts near the top on the left and slopes downward to the right: fine at low pitches, weaker at high pitches. That's the classic shape of age-related and noise-related loss, and it's exactly why people say "I hear you, I just can't make out the words": the vowels arrive, the consonants don't. (More on that in why you can hear but not understand.)
Things worth noting on any audiogram: how far down the line sits (degree), whether it slopes (which pitches), and whether the ears differ (asymmetry, a reason to get checked professionally).
Get your own audiogram in 3 minutes, drawn with the same O and X conventions, saved to Apple Health.
Get HearAge for iPhoneFrequently asked questions
What is a normal audiogram?
For adults, 25 dB HL or better at every tested frequency is generally considered normal. The closer the line stays to the top, the better.
What do the O and X symbols mean?
O is the right ear, X is the left ear, tested through headphones. Right is drawn in red, left in blue.
Is 30 dB hearing loss bad?
It's in the mild band (26–40 dB HL): soft speech and conversation in noise become hard. Noticeable, worth acting on, far from severe.
References
- ASHA, Degree of hearing loss
- NIDCD, Quick statistics about hearing
- How HearAge measures your thresholds: our methodology