Usual with hearing-impairment among Swedish hunters
Håkanson & Gingsjö asked 874 Swedish hunters about hearing-impairments and the use of hearing protection. The studie showed that 45% of the interviewed hunters experienced that they had reduced hearing and/or tinnitus. Most of the hunters used hearing protection during practis shooting. But 90% said that they didn't use hearing protection during the actual hunting! (Håkansson, B. & Gingsjö, A. Use of hearing protection, firing sound load, hearing problems and attitudes about hearing protection among the Swedish hunters. Technical report 1:95, ISBN 91-7546-068-8, Chalmers University of Technology, 1995)

Greenland: differences between men and women's hearing
Among the Greenlandic men in a small village 70% had a confirmed hearing-impairment while the women in the village had normal hearing. The men started hunting seal etc. at the age of 10-11 and this was the explanation for the differences in hearing. (Counter, S.A & Klareskov, B., Hypoacusis among the Polar Eskimos of Northwest Greenland, Scandinavian Audiology 19, s. 149-160, 1990)

Hearing-impairment among American shooters
Griffing studied 400 American shooters hearing levels and in 45% of the cases they found confirmed hearing-impairments. Similar results where found in a study of the hearing of 1538 American men in the age of 48-92 years. Men that had been hunting during the last year had a higher probability for hearing-impairment of 1,4 compared to the non-shooters in the study. Men doing clay-pigeon shooting during the last year had twice as many hearing-impairments as the non-shooters. Here also is the conclusion that hearing protection prevents hearing-impairment. (Griffing, T.S., HPDs: Arming shooters against risk of hearing loss, Hearing instruments, 45(4), s. 34-35, 1994 och Recreational firearms use and hearing loss, Archives of Family Medicine, vol. 9, April 2000)