Device May Let Humans Communicate With Dolphins
A new dolphin speaker device could one day help us talk with these remarkably intelligent life forms, scientists say. Dolphins live in a world of sound far beyond our own. They can distinguish very small differences in the frequency or pitch of sound waves, and can hear and generate low-frequency sounds below 20 kilohertz that lie within human capabilities, as well as high-frequency sounds of up to more than 150 kilohertz, well beyond the range of our hearing. In addition, dolphins not only can produce tones just as humans do, but they can also communicate at a variety of frequencies simultaneously.
With whistles, burst-pulse sounds and clicks, dolphins use sound not only to communicate and to scan their surroundings and prey in the dark sea (called echolocation). Now scientists have developed a prototype dolphin speaker that can project the full range of all of the sounds dolphins make — from those used in communication to echolocation clicks.