Eustachian Tube Dysfunction and Tinnitus: A Rapid Review of the Potential Complementary Role of Acoustic Immittance.

Abstract

To critically examine the available evidence regarding the complementary role of acoustic immittance in patients with tinnitus and suspected Eustachian tube dysfunction (ETD), while distinguishing clinical evidence from indirect and mechanistic support. A rapid review was updated and reconstructed in accordance with preferred reporting items for systematic reviews and meta-analyses (PRISMA) 2020. Google Scholar and Dimensions were searched de novo from inception through August 2026; PubMed/MEDLINE and SciELO were updated from March 31, 2024, onward to complement the original searches completed on March 30, 2024. Eligible primary human studies explicitly reported tinnitus and also evaluated ETD/patulous Eustachian tube (PET) and/or acoustic immittance. Twelve studies were included in the qualitative synthesis. The 12 included studies were heterogeneous. Three studies co-assessed ETD/PET, tinnitus, and an acoustic-immittance measure in the same clinical population, but none evaluated whether acoustic immittance can diagnostically identify tinnitus attributable to ETD. Tympanometric or compliance-based measures provided objective information on middle-ear pressure regulation and PET, whereas acoustic reflex and middleear muscle reflex studies in tinnitus populations were predominantly indirect or mechanistic. The added value of reflex testing for ETD-associated tinnitus remains unproven. Acoustic immittance may provide complementary information when tinnitus coexists with clinical suspicion of ETD or middle-ear dysfunction. Tympanometry is the most clinically defensible component, but findings require correlation with symptoms, otoscopy, audiometry, ear-canal volume, laterality, and ETD subtype. Acoustic reflex/MEM testing should be used selectively because its specific diagnostic value in this context remains uncertain.