Audiometry with nasally presented masking noise: novel diagnostic method for patulous eustachian tube.

Objective: Nasal-noise masking audiometry was developed to assess the acoustic transfer function from the nasopharyngeal cavity to the middle ear via patulous eustachian tube (ET).

Study Design: Prospective.

Setting: Tertiary referral center.

Patients: Twenty-seven ears of 18 patients with patulous ET and 20 ears of 10 healthy subjects with no history of ear disease or complaints of aural symptoms.

Main Outcome Measures: Audiometric measurement was conducted with and without masking noise presented in the nasal cavity.

Results: The masking effect of nasally presented noise caused elevation of the threshold for the tone presented in the external auditory canal. This threshold elevation was significantly greater, particularly in the lower-frequency region, in ears with patulous ET and was decreased to the normal range after obstructive treatment of the patulous ET.

Conclusion: Nasal-noise masking audiometry is a simple and effective way to identify patulous ET.