Experiments on the mechanism of underwater hearing

Abstract

Conclusion: The findings suggest that underwater sound perception is realized by the middle ear rather than by bone conduction, at least in shallow water conditions.

Objective: To prove whether underwater sound perception is effected by bone conduction or by conduction via the middle ear.

Methods: Five divers, breathing through snorkels, were tested in a swimming pool, to determine whether a sound was louder when the acoustic source placed was in front of the head in comparison with a lateral application facing the ear region. The second experiment investigated whether sound perception is influenced by ear protection plugs in underwater conditions. Also, the effect of a 5 mm thick neoprene hood was determined, with and without an additional perforation in the ear region.

Results: Sounds were louder when applied from a position laterally facing the ear, louder without than with a protection plug, louder without than with a neoprene hood on, and louder when the neoprene hood had a perforation in the region of the ear than with an intact hood.