Doc's Proplug Ear Plugs protect the ear by keeping a warm pocket of air in the canal and keeps most cold water out without impeding hearing and balance.
The Scott's valve, a hole (vent) in the inner diaphragm, allows the transfer of air and thus sound waves and differences in air pressure while water does not pass through the hole in wipeouts. The surface water tension on the outside of the valve keeps the water out, but lets air and voice in. Anyone with severe narrowing of the ear canal can avoid frequent water blockage by wearing Proplugs. In some cases, surfer's ear can only be cured through surgery. However, the latest research suggests that severe exostosis can be slowed by keeping the ears warm around the clock with plugs and woolen/silk head bands, hats, or hoods, especially when sleeping at night.