Swimming with earplugs: are they worthwhile?

The ears of 30 children were examined before and after swimming. Each ear was plugged with cotton wool which was then covered with petroleum jelly. Of the 60 earplugs, 4 (6.6%) were lost while swimming and water was seen in the ears. The remaining 56 (93.3%) earplugs were still in place after swimming. The plugs were removed and the ears, on otoscopy, were found to be dry. In a separate experiment with volunteers, water was instilled into 10 ear canals. Either 1 drop (0.05 ml), 2 drops (0.1 ml) or no water was instilled. Nine of the 10 ears were correctly judged to have either 'no water' or 'water present', suggesting that as little as 0.05 ml of water in an ear canal can be detected otoscopically.