A device to communicate with dolphins!

Washington: Scientists have developed a new dolphin speaker device which they say could help one communicate with these remarkably intelligent mammals.

Dolphins live in a world of sound far beyond our own. They can distinguish very small differences in the pitches of sound waves and can hear, and generate low-frequency sounds below 20 khz, as well as high-frequency sounds of over 150 khz, which is well beyond the range of human hearing.

In addition, they produce special sounds to communicate with others and to scan their surroundings and prey in the dark sea (called echolocation).

Acoustic research of dolphins to date has mostly focused on recording their sounds and measuring their hearing skills. Few audio playback experiments have been attempted, since it`s difficult to find speakers that can project from a wide range of low to high frequencies like dolphins do.

Now, scientists in Japan have devised a prototype dolphin speaker that can project the full range of all of the sounds the mammals make -- from those used in communication to echolocation clicks.

To develop the device, the researchers used piezoelectric components that convert electricity into physical movement and vice versa. These components were capable of broadcasting both high-frequency and low-frequency sounds.

They precisely tailored the sizes of these components and the acrylic disk to create an extremely broad range of sounds.

"I am happy if we can communicate with dolphins using the dolphin speaker," lead researcher Yuka Mishima of the Tokyo University of Marine Science and Technology told LiveScience.

The dolphin speaker, which was developed just a few weeks ago, has not been tested yet. Mishima and colleagues plan to work with such scientists using the new speaker.

The idea is to broadcast specific series of vocalisations and then record the responses; over time, this back and forth could someday both reveal what dolphins are "saying" and allow possible human-dolphin communication, the researchers detailed at Acoustical Society of America meeting in Hong Kong.

"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 of New College of Florida in Sarasota who wasn`t involved in the new research.

As to whether or not this invention could one day result in a human-dolphin translator device, "I think we have a lot to learn about dolphin vocalisations -- their productions are complex," Harley said.

"There is still a lot of basic perceptual and acoustic analysis that needs to be done before we can make strong claims about how dolphins are using their vocalisations," he added.