Condition · Outer / middle ear

Patulous Eustachian Tube

An abnormally open tube — breathing-synchronous admittance fluctuation

A tube that will not stay closed

A patulous Eustachian tube transmits nasopharyngeal pressure changes directly to the middle ear. During tympanometry and reflex recording the admittance baseline fluctuates in synchrony with respiration, which can obscure or mimic a reflex deflection.

Recognising the artefact

The breath-hold test is the bedside confirmation: the rhythmic baseline movement stops when respiration stops. Symptoms of autophony — hearing one's own voice and breathing loudly — support the diagnosis.

The reflex signature

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

A normal four-cell grid once the respiration artefact is recognised; the breath-hold test removes the fluctuation.

Reflex decay

0s2s4s6s8s10s0%50%100%50% criterion
Negative (normal) decay — amplitude is well maintained across the 10-second hold. Decay is not the relevant measure here; the diagnostic feature is the breathing-synchronous baseline fluctuation rather than a true reflex abnormality.

Pure-tone audiogram

0204060801002505001k2k4k8kFrequency (Hz)Hearing level (dB HL)
○ Right ear✕ Left ear
Hearing is typically normal; symptoms are dominated by autophony rather than hearing loss.

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

References for this page

  1. Henry DF, DiBartolomeo JR (1993). Patulous Eustachian tube identification using tympanometry. Journal of the American Academy of Audiology, 4(1), 53–57.
  2. Gelfand SA (2009). Essentials of Audiology. Thieme, 3rd edition.
  3. Katz J (Ed.) (2015). Handbook of Clinical Audiology (7th ed.). Wolters Kluwer, Philadelphia.
Want to contrast this with another condition? The comparison tool places any two reflex signatures side by side.