Does Diving Affect Your Hearing?

Ear injuries make up about 65 percent of dive disorders. Decompression sickness can affect the inner ear, where inert gas bubbles form and grow. Barotrauma can occur when divers have trouble equalizing pressure in the middle ear during a descent. But what's the longterm effect of regular diving on one's hearing? While a lot of old-time divers seem to blame their hearing loss on diving, it just isn't so. The most recent studies of the topic provide a pretty consistent answer: long-term diving doesn't have much of an effect on hearing.

In a recent study, researchers tested the hearing of 748 military divers in the Singapore Navy enlisted between 2001 and 2010, who averaged 200 dives over two years to maximum depths of 100 feet. Preenlistment and pre-discharge audiograms were used to evaluate their hearing thresholds. The divers' hearing levels in the left ear were not affected, except for a marginal decrease in hearing at the 2,000 Hertz level. In the right ear, there was a marginal decrease in hearing at the 500Hz, 1,000Hz and 2,000Hz level.

Overall, there were more low-frequency changes compared to high-frequency changes (4,000Hz and 8,000Hz) changes in both ears, with a larger number of changes noted in the right ear. However, no diver had a hearing threshold increase greater than 20 decibels, or exceeded the hearing threshold levels required of military divers. The researchers concluded that these changes were only marginal and without physiological significance.

The above is consistent with slightly earlier study findings from researchers at the University of Heidelberg in Germany. In papers for the journal Undersea and Hyperbaric Medicine, they concluded that, in sport divers without any history of scuba-related ear injury (e.g., barotrauma), neither central nor peripheral hearing appeared adversely affected to any significant degree.

In short, diving-related hearing loss is largely limited to commercial divers who are exposed to loud noises, and divers who have experienced barotrauma of the ear. The recreational diver who equalizes appropriately and sustains no ear injuries doesn't appear to be at significant risk for diving-related hearing loss or tinnitus.

- - Doc Vikingo

"Does diving affect the hearing of Asian military divers? A study in the Republic of Singapore Navy," by J. Chang, G, Chan and KC Tang, Undersea and Hyperbaric Medicine, vol. 41, no.1, pgs. 41-46.