Dolphins make two types of sound; social sounds - squeals and whistles, much of which we humans can hear, and very high-frequency bio-sonar bursts, which we only hear as clicks. While we haven’t figured out whether their social sounds are structured into a vocabulary - where certain sounds ‘mean’ certain things, we do know that some dolphins have “signature whistles” which serve as names – for themselves, and for others.Bio-sonar are bursts of high-frequency energy which they project out into th