Admittance tympanometry with 2‐kHz probe tones in patients with low‐frequency hearing loss

Abstract

To assess the reliability of admittance tympanometry with 2-kHz probe tones in diagnosing ears with endolymphatic hydrops in patients with low-frequency hearing loss. Case-control study. Thirty-six Japanese patients with low-frequency hearing loss (including 21 with Mènière disease, three with delayed endolymphatic hydrops, and 12 with acute or repetitious low-frequency sensorineural hearing loss), 18 patients with other types of hearing loss, and 16 subjects with normal hearing were enrolled at University of Tokyo Hospital. We measured the width of the splitting peaks in the admittance tymapnometry with 2-kHz probe tones. Widths of the probe pressure corresponding to splitting peaks of admittance (Y) tympanometry were significantly greater in the ears with endolymphatic hydrops than in the ears without endolymphatic hydrops in patients with low-frequency hearing loss. Furthermore, the widths in the ears with endolymphatic hydrops were greater than those in ears with other types of hearing loss. Widths of >255 daPa were observed in 38% of ears with endolymphatic hydrops and low-frequency hearing loss and in 21% of ears with other types of hearing loss. The current study demonstrated that wide splitting peaks of Y tympanometry are more frequently observed in ears showing low-frequency hearing loss than in those with other types of hearing loss, indicating that Y tympanometry can be used to diagnose endolymphatic hydrops in daily practice.