Dolphins and porpoises use echolocation for hunting and orientation. By sending out high-frequency sound, known as ultrasound, dolphins can use the echoes to determine what type of object the sound beam has hit.
However, researchers from Sweden and the US have now discovered that dolphins can actually generate two sound beam projections simultaneously.
"The beam projections have different frequencies and can be sent in different directions. The advantage is probably that the dolphin can locate the object more precisely," says Josefin Starkhammar, an engineering physicist and doctor in Electrical Measurements at Lund University. "It is also somewhat remarkable that this has only been discovered now. Research has been carried out on dolphins and echolocation since the 1960s."
One explanation as to why the discovery has taken so long is that this research requires recently developed and quite advanced measuring equipment and signal processing techniques. In addition, until now it has mostly been biologists who have conducted research on dolphins, and their expertise is often not in this specific area of technology.
Bats also use echolocation and there are a few species of shrew and some cave-dwelling birds which use a simpler form of the method. Even humans have developed devices that use echolocation and ultrasound technology.
"However, dolphins' echolocation is in many ways much more sophisticated. Evolution has had the possibility to hone it over millions of years. Therefore, we humans have a lot to learn from dolphins. What is more, the knowledge could be important in finding ways to protect dolphins, for example from noise disturbance." says Starkhammar.
Nobody really knows the scale of underwater noise disturbance but it is likely to have significant negative impacts on a large number of different sea-dwelling animals so research like this can only help.
Throughout history humans have gained inspiration for new designs and technologies from the natural world. To do this we need to study them. The more we understand about the amazing capabilities of the creatures with which we share this planet the more we must surely respect and want to protect them.