DISEASE PAGE

Noise-Induced Hearing Loss

A high-frequency emission loss with a notch — often visible before the audiogram changes.

The OAE signature

  • Reduced emission amplitude concentrated in the high frequencies, often with a notch around 3–4 kHz mirroring the audiometric notch.[5]
  • Amplitude reduction can appear before a measurable shift in pure-tone thresholds, making the OAE a sensitive early monitor.[3]
0 ms20 ms
— Normal ear— Noise-Induced Hearing Loss
Simulated TEOAE comparison. Educational signal model — not recorded patient data.

Audiogram companion

The pure-tone audiogram below accompanies the OAE signature. Reading the two together — what the threshold shows and what the emission shows — is the core diagnostic skill.

0204060801002505001k2k4k8kFrequency (Hz)
○ Right — PTA 15 dB (Normal)✕ Left — PTA 18 dB (Normal)
Pure-tone audiogram companion. dB HL increases downward, following clinical convention. Illustrative thresholds — not recorded patient data.

Why the emission looks this way

  • Intense sound preferentially damages outer hair cells in the basal, high-frequency region of the cochlea, reducing emission output from exactly those frequencies first.[4]

TEACHING POINT

Serial high-frequency DPOAEs are valuable for occupational monitoring because they flag cochlear stress earlier than conventional audiometry.[3]

Sources for this page are listed on the References page. Browse all condition patterns from the atlas home.