Scientists report that dolphins can call each other by name when they whistle. That makes them the only animals besides humans known to recognise such information on their identity. Scientists have long known that dolphinsâ whistling calls include repeated information thought to be their names; a new study indicates that the mammals recognise these names even when voice cues are removed from the sound. A dolphin might be expected to recognise its name if called by its mother, but the new study found most dolphins recognised names even when emitted without inflection or other vocal cues. Two dolphins may even refer to a third by its name. Scientists already know that dolphins responded to whistles, but wondered if something in the voice of the whistling dolphin was making the identity clear, or if the name itself was enough for recognition. To find out, they studied bottlenose dolphins. Instead of playing recordings of actual dolphins whistling, the researchers synthesized signature whistles with the callerâs voice features removed and played them to dolphins through an underwater speaker. In 9 out of 14 cases, the dolphin turned toward the speaker if it heard a whistle that sounded like a relativeâs. The scientists stopped short of saying dolphins might have a human-like language.