Extended high-frequency audiometric analyses of tinnitus patients exhibiting normal hearing on conventional pure-tone audiometry

Background While hearing loss is the greatest risk factor associated with developing tinnitus, some tinnitus patients exhibit no hearing loss on conventional pure-tone audiometry (PTA). Objectives This study was developed to assess whether tinnitus patients with normal hearing as measured via conventional PTA would exhibit differences from normal controls upon extended high-frequency (EHF) audiometric evaluation. Methods In total, 102 tinnitus patients were separated into unilateral and bilateral tinnitus groups. Age- and sex-matched controls without tinnitus were enrolled. Results No significant differences were observed when comparing EHF audiometry results in the 9-14 kHz range between controls and tinnitus patients, with only left-sided tinnitus ears exhibiting higher hearing thresholds than contralateral ears at 9, 10, and 14 kHz. Relative to normal controls, the hearing thresholds in the 2-8 kHz range for tinnitus ears were significantly increased. Conclusions and significance Relative to controls, tinnitus patients with normal hearing did not exhibit any significant hearing loss in the EHF range. Unexpectedly, tinnitus patients with normal hearing exhibited significant hidden hearing loss in the conventional frequency range rather than in the EHF range. For patients with normal hearing, it appears to be unnecessary to conduct EHF examinations to detect hearing loss in the EHF range.