Shooting history and presence of high-frequency hearing impairment in swedish hunters: A cross-sectional internet-based observational study

Abstract

The aim of this cross-sectional study among Swedish hunters was to examine the association between shooting history and presence of high-frequency hearing impairment (HFHI). All hunters registered with an e-mail address in the membership roster of the Swedish Hunters’ Association were invited via e-mail to a secure website with a questionnaire and an Internet-based audiometry test. Associations, expressed as prevalence ratio (PR), were multivariately modelled using Poisson regression. The questionnaire was answered by 1771 hunters (age 11-91 years), and 202 of them also completed the audiometry test. Subjective severe hearing loss was reported by 195/1771 (11%), while 23/202 (11%) exhibited HFHI upon testing with Internet-based audiometry. As many as 328/1771 (19%) had never used hearing protection during hunting. In the preceding 5 years, 785/1771 (45%), had fired >6 unprotected gunshots with hunting rifle calibers. The adjusted PR of HFHI when reporting 1-6 such shots, relative to 0, was 1.5 [95% confidence interval (CI) 1.1-2.1; P = 0.02]. We could not verify any excessive HFHI prevalence among 89 hunters reporting unprotected exposure to such gunshot noise >6 times. Nor did the total number of reported rifle shots seem to matter. These findings support the notion of a wide variation in individual susceptibility to impulse noise; that significant sound energy, corresponding to unprotected noise from hunting rifle calibers, seems to be required; that susceptible individuals may sustain irreversible damage to the inner ear from just one or a few shots; and that use of hearing protection should be encouraged from the first shot with such weapons.

Cigarette- and snus-modified association between unprotected exposure to noise from hunting rifle caliber weapons and high frequency hearing loss. A cross-sectional study among swedish hunters

“…A brief questionnaire to the nonparticipants did not signal any important differences between participants and nonparticipants in terms of shooting exposure or subjective hearing ability, but the response rate was insufficient to ensure representativeness vis-à-vis all nonparticipants. [1] The prevalence of cigarette smoking and snus use among participants was well in line with Swedish statistics. [2526] Our overall evaluation was that the observed effect modification was not likely to be attributable to selection bias, but our results must be cautiously interpreted.…”

“…The InternetAudio test has been formally validated, with a clinical pure-tone air-conducted audiometry as gold standard, in 72 volunteers with a broad range of hearing ability, resulting in satisfying results. [21] The test was also further validated under authentic conditions during the present survey[1] with similar results as the formal validation. [21]…”

“…[1] E-mail invitations were sent to 27,063 hunters with e-mail addresses in the membership roster of the Swedish Hunters Association. Nonresponders received two e-mail reminders.…”

“…On the basis of the results of our previously published analysis,[1] the main exposure of interest was the number of shots with HRC weapons (generating the highest SPL in sports hunting) fired without hearing protection in the preceding 5 years, categorized into 0, 1–6, and >6. The outcome was the presence of HFHI, ascertained by the InternetAudio test.…”

“…[1] Although susceptible individuals who experience acute effects tend to avoid further unprotected shooting with such weapons and thus report no more than a couple of such shots, others seem to withstand similar audio trauma without any adverse sequels; they typically report large numbers of unprotected shots with HRC weapons, but their audiometry results remain largely normal.…”