The Association Between Extended High-Frequency Loss and Vestibular Function Among Young Earphone Users

Introduction: Unsafe earphone listening habits can pose a risk of hearing loss, and early audiogram threshold shifts could occur at extended high frequencies (EHFs, 9-16 kHz) despite normal thresholds at the conventional test frequencies (0.25-8k Hz). Preliminary reports also suggest that regular earphone users could suffer from vestibular impairment. This study investigated the vestibular function among young adult users with normal audiograms at the conventional test frequencies with and without EHF hearing loss. It is hypothesised that those with EHF loss from earphone usage suffer early deficits in vestibular function. Methods: Regular earphone users aged 12 to 25 years were questioned regarding their earphone listening behaviours. Their audiogram thresholds were determined at conventional and EHFs and grouped into those with and without EHF loss. Each participant underwent cervical vestibular evoked myogenic potential (cVEMP), subjective visual vertical (SVV), and video Head Impulse Test (vHIT) to assess the function of their saccule, utricle, and semicircular canals, respectively. Results obtained from these parameters were compared between those with and without EHF loss. Results: While all 131 subjects tested had normal audiogram thresholds at 0.5 to 8 kHz, 15.3% had EHF hearing loss. The average duration of earphone usage per day was significantly longer in those with EHF loss than those with normal EHF ( P = .008), but their preferred listening volume and total years of listening were comparable. While there was no statistical significance in the findings of the SVV and VHIT test, a significant reduction of the amplitude cVEMP was noted ( P < .001), suggesting that those with EHF hearing loss may also have early vestibular damage, particularly to the saccule. Conclusion: Earphone users with EHF loss may have concomitant early saccule damage. cVEMP may be an alternative tool to detect early noise-induced cochlear damage, although a large cohort study is required to justify this.