Evaluating Middle Ear Absorbance and Resonant Frequency in Patulous Eustachian Tube Patients Using Wideband Tympanometry.

OBJECTIVE

This study aimed to investigate the utility of wideband tympanometry (WBT) in diagnosing patulous Eustachian tube (PET) by examining differences in middle ear absorbance and resonant frequency between PET patients and controls.

STUDY DESIGN

This is a retrospective observational study.

SETTING

This study was conducted at Iwate Medical University Hospital.

SUBJECTS AND METHODS

A review of medical records identified 25 ears of 19 PET patients and 18 ears of 9 patients with sensorineural hearing loss or vertigo as a control group. Diagnosis of PET was based on Japan Otological Society criteria. WBT was conducted across frequencies of 226-8000 Hz, measuring ambient pressure absorbance ratios and peak pressure absorbance ratios, as well as resonant frequency (RF) values.

RESULTS

The PET group demonstrated significantly lower absorbance at 1000 Hz ( = 0.006) compared with the control group, with no significant differences observed at other frequencies. The RF was significantly reduced in the PET group compared with controls ( < 0.001), indicating alterations in middle ear mechanics associated with PET. The Valsalva maneuver had no significant effect on absorbance values across frequencies.

CONCLUSION

WBT is a valuable diagnostic tool for PET, with significant reductions in 1000 Hz absorbance and resonant frequency in PET patients. These parameters may serve as markers for PET, aiding in its differentiation from other middle ear conditions.