Coral larvae are more likely to settle on damaged reefs if they hear noise. Researchers set up underwater speakers to mimic the sounds of the reef. The further the speakers were from the reef, the fewer corals they found. Coral reefs are home to almost a quarter of all marine animals and can slow down storm waves. They are threatened by rising water temperatures, ocean acidification and pollution. The researchers are trying to stop coral deaths or reactivate reefs that have already been damaged. The results are promising, but it is still unclear whether all coral species react to noise.