Subclinical auditory effects of recreational diving: a multidimensional audiological assessment beyond the audiogram

This study aimed to evaluate peripheral auditory function and Eustachian tube function in individuals engaged in recreational diving compared with non-diving controls, via a multidimensional audiological assessment approach.

A total of 49 participants aged 18-50 years were included, comprising 24 individuals actively engaged in scuba or free diving who reported no auditory or neurotological complaints prior to initiating diving, and 25 non-diving controls without any otologic or neurologic disorders. All participants underwent otorhinolaryngologic examination, conventional and wideband tympanometry, Eustachian tube function (ETF) testing, pure-tone audiometry, and distortion product otoacoustic emission (DPOAE) measurements. The subjective ETF was assessed via the Eustachian Tube Dysfunction Questionnaire-7 (ETDQ-7).

Pure-tone audiometry, speech audiometry, and conventional tympanometric measurements were not significantly different between the groups (all p > 0.05). In the diver group, the middle ear resonance frequency was significantly lower in at least one ear than in the control group (p < 0.05). Objective ETF testing revealed a higher frequency of Eustachian tube dysfunction in diver group (p < 0.05), and ETDQ-7 scores were also significantly higher in this group (p < 0.05). Additionally, DPOAE measurements revealed significant group differences at higher frequencies, with reduced amplitudes observed in divers (p < 0.05).

Recreational diving may be associated with subclinical alterations in middle ear mechanics, Eustachian tube function, and cochlear outer hair cell activity that are not detected by standard audiometric evaluations. The inclusion of wideband tympanometry, objective ETF testing, and high-frequency DPOAE measurements may provide complementary information for audiological evaluation of individuals engaged in recreational diving.