Condition · Outer / middle ear

Tympanic Membrane Perforation

A hole in the eardrum — reflex absent on the probe side, large ear-canal volume

No sealed cavity to measure

A perforation removes the sealed boundary the immittance meter depends on. Tympanometry typically shows a very large equivalent ear-canal volume, and the reflex is absent on the probe side because the contraction cannot be resolved against the enlarged, leaky cavity.

The reflex signature

Stim. Right
Stim. Left
Probe Right
Absent
Absent
Probe Left
Present
95 dB HL
Present
90 dB HL
The characteristic four-cell grid for this condition.

A probe-ear column of absent responses, accompanied by a large equivalent ear-canal volume on tympanometry.

Reflex decay

0s2s4s6s8s10s0%50%100%50% criterion
Negative (normal) decay — amplitude is well maintained across the 10-second hold. Not assessable on the affected side.

Pure-tone audiogram

0204060801002505001k2k4k8kFrequency (Hz)Hearing level (dB HL)
○ Right ear✕ Left ear
Right ear: conductive loss, its size depending on the perforation's size and location.

Frequencies plotted: 250, 500, 1k, 2k, 4k, 8k Hz.

References for this page

  1. Gelfand SA (2009). Essentials of Audiology. Thieme, 3rd edition.
  2. Blevins NH, Karmody CS (2003). Chronic myringitis: prevalence, presentation, and natural history. Otology & Neurotology, 24(1), 3–10.
  3. Hall JW (2014). Introduction to Audiology Today. Pearson, Boston.
  4. Katz J (Ed.) (2015). Handbook of Clinical Audiology (7th ed.). Wolters Kluwer, Philadelphia.
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