Ear exostoses or Surfer's Ear
These are benign bone formations in the ear canal which cause varying degrees of hearing impairment.
This condition is named after its high rate of occurrence in people who practise watersports which expose them to water and wind, such as surfing.
To avoid the unpleasant consequences of bone exostoses, you need to keep the ear canal as dry and warm as possible, especially in cold and windy conditions.