Dolphins are known to make three types of sounds: whistles, clicks and burst pulses. Whistles are thought to be identification sounds, like names, while clicks are used to navigate and to find prey with echolocation.
Burst pulses, which can sound like quarreling cartoon chipmunks, are a muddy mixture of the two, and Dr. Herzing believes that much information may be encoded in these sounds, as well as in dolphins’ ultra-high frequencies, which humans cannot hear.
The two-way system she will test next year is being developed with artificial intelligence scientists at Georgia Tech. It consists of a wearable underwater computer that can make dolphin sounds, but also record and differentiate them in real time. It must also distinguish which dolphin is making the sound, a common challenge since dolphins rarely open their mouths.
In the new system, two human divers interact in front of dolphins: First they play a synthesized whistle sound, then one hands the other a scarf or a piece of seaweed. The idea is to establish an association between sound and object. Dolphins are excellent mimics, and the hope is that they will imitate the whistle to request an object or initiate play.
“I think if they pick up on it,” Dr. Herzing said, “they’re going to be excited and say, ‘Oh, my gosh, now I have the power to get what I want in real time.’ ”
Still, she is quick to play down expectations, noting that the system is still in development.
“We’re not talking to dolphins,” she said, adding, “We’ll keep it simple and then we can potentially expand it.”
And while other researchers praise her work, they point out that of dolphin-human communication has often fallen short of expectations.
“It depends on what you mean by communicate,” Dr. Kuczaj said. “I can communicate with my dog, too. But do I have conversations with my dog? Well, if I do they’re very one-sided.”