Together with Dr Thad Starner, the technical lead researching Google Glass at the Georgia Institute of Technology, the researchers have created the Cetacean Hearing and Telemetry (CHAT), the world's first prototype dolphin translator.
CHAT is a small underwater keyboard fitted to the arm of a diver. It has four symbols which correspond to four artificial whistle sounds that researchers have taught the dolphins to mimic. Each sound represents an item the dolphins like to play with, such as seaweed, rope or a scarf. By pressing a button on the keyboard, the diver can activate a sound through an underwater speaker.
Since 2011, they have digitised the database and used it to collect data on all the different whistle sounds they make, many of which the human ear cannot hear, since dolphins' whistles are on frequencies up to 200 kilohertz, which is 10 times higher than the highest pitch a human can hear."
Link to Original Source