A new device that can mimic the sound of dolphins could one day help humans talk with the remarkably intelligent creatures, scientists say. While acoustic research on dolphins has focused on recording their sounds and testing their hearing abilities, very few audio playback experiments have been attempted, since it is difficult to find speakers that can project the range of low to high frequencies dolphins are capable of, researchers said. Japanese scientists have developed a prototype dolphin speaker that can emit the full range of dolphin sound, from those used in communication to echolocation clicks, many of which are outside the range of human hearing, LiveScience.com reported Thursday. The researchers employed components that convert electricity into physical movement and vice versa, so the speaker can both emit and record dolphin sounds. Scientists say the speaker can broadcast specific series of dolphin vocalizations and then record the responses, with the hope that this back and forth could someday both reveal what dolphins are \"saying\" and allow possible human-dolphin communication. \"I am happy if we can communicate with dolphins using the dolphin speaker,\" researcher Yuka Mishima at the Tokyo University of Marine Science and Technology said. The device could help understand what different sounds mean to dolphins, scientists said. \"We know very little about how dolphins classify their own sounds -- we need more perceptual studies to find out, and this equipment may help us do that,\" said Heidi Harley, a comparative cognitive psychologist at New College of Florida in Sarasota, who wasn\'t involved in developing the dolphin speaker.