Sea anemones could soon do a lot to help those of us living above the water. Researchers have discovered that proteins used by starlet sea anemones to repair their cells also repair the sound-sensing cells in mice and other mammals. If you bathe cells in those proteins for long enough (the team tried for an hour), they rapidly restore molecular links that bundle hearing-related hair cells together. In theory, you could reverse hearing damage among cells that haven't been permanently lost -- that exceptionally loud concert might not permanently limit your listening enjoyment.
There's a lot of work to be done before there's an actual treatment. However, scientists don't think you'd always need anemone cells to make this work. At least in mice, there are repair proteins that parallel those from the underwater creatures. If researchers can find a way to improve their effectiveness (mammal proteins are much less useful right now), you wouldn't need to harvest them from sealife to deliver effective treatments.