Here is the fascination of exploring a new frontier -- communication with ocean mammals. Here are descriptions of exciting experiments and the immense possibilities they evoke. Here is startling information about mammal brains and their functioning. Dr. Lilly recounts the results of research to the present, describes the programs now being undertaken, and predicts potential future relationships between man and dolphin.

" I envision the day when the current oceanaria will progress from being circuses for dolphins to being interspecies schools, education dolphins and humans about one another." -- Dr. John C. Lilly

Extensive studies of both the human and dolphin thresholds for hearing at various frequencies show that the bottle-nosed dolphin detects and uses signals of approximately four-and-one half to ten times the frequencies that humans normally use.

Dolphins can hear the frequencies of human speech in the lower end of their detection spectrum. They can also produce sounds in this region as well as in the upper-frequency regions that they normally use to communicate.

A dolphin can open his blowhole in the air and produce sounds; however, he does this only in the presence of humans who speak in air. We discovered that dolphins will try to mimic and improve their copies of human speech in the presence of humans who speak to them loudly.

The dolphin's ability to use his communicative sound in man's presence is not unexpected when his large brain is compared with that of the human.

Two dolphins communicating sound like three dolphins. They may face each other and use the laryngeal tight sonar beam for communication when they do not want somebody else to know about their communication. We often found them doing this in our laboratory, and every so often we had the opportunity of having a hydrophone between them and we would then detect the fact that they were doing this. We could not hear it of course, it was too high a frequency for our ears, but we could show it on a cathode-ray oscilloscope and record it on high-frequency tape recorders.

I do not think that dolphins distinguish their sonar from their communication with the nasal emitters. The nasal emitters emit longer wavelength sound than does the laryngeal emitter. This means that they have a 360 degree solid angle "sonar'' in the two emitters near the blowhole as opposed to the tight beam emitter of the larynx. This means that they can detect objects behind, above, below or ahead of them with the nasal emitters, and then with the laryngeal emitters they can turn on any interesting object and examine it in detail.

They do not distinguish between sonaring and communicating; in other words they are quite capable of sending holographic sonic pictures to one another with their communication apparatus. They can then use these pictures in symbolic ways similar to the way that we use the printed versions of words spoken out loud.

This implies an immense complexity of acoustic memory and of acoustic portrayal, way beyond anything that we have achieved either in simulations in computers or in terms of concepts having to do with acoustic events. Only our most sophisticated and advanced mathematics can even approach an analysis of this kind of a system.