Whales and dolphins live in an environment that requires them to continually perceive their world using both vision and sound. Research has primarily focused on Odontocetes [toothed whales and dolphins], who have developed a remarkable sensory ability for locating food and for navigation underwater.
They are able to produce a variety of sounds by moving air between the sinuses in the head. These sounds are reflected or echoed back from objects, in a process called ‘echolocation’. The echoes from these sounds provide information about the seafloor, the shorelines, underwater obstacles, water depth, and the presence of other animals underwater.
Echolocation is so effective in bottlenose dolphins that they can detect a small object of less than 8 cm at distances of over 110 m, [more than a football field length]. They have the ability to focus and change the shape of the echolocation beam to facilitate more precise detection. Sperm whales can identify a human at up to a mile away. A recent theory suggests that very high intensity focused sounds may be used to stun or disorient prey in hunting.
Regarding resolution details, human vision, using a pulsed light source, for example a fluorescent light bulb, or the sun for that matter, is capable of detecting a high degree of detail from the reflected light off the object observed. By comparison, the auditory pulse frequency used and detected by cetaceans is much greater in frequency than either the visual or auditory signals humans can detect. And thus contains more information that is assimilated by cetaceans and used to analyze their environment.
It is believed that cetaceans see with sound. The auditory and visual processing centers in their brains are adjacent to each other. The cetacean auditory system is primarily spatial, more like human eyesight. It is believed that these two parts of their brain work together in what is referred to as ‘cross modal’ communication, allowing them to process sound with the visual receptors within their brain. Echolocation is extremely sensitive and it is believed it may provide toothed whales and dolphins with a three dimensional view of their world.
Cetaceans can reproduce echolocation and other communication sounds with extreme precision, like a fax machine. It appears they are able to project an “auditory image” that replicates the sonar message they receive. So, a dolphin wishing to convey an image of a fish to another dolphin can literally send an image of the fish to the other animal. The equivalent of this in humans would be the ability to create instantaneous holographic pictures to convey images [ideas] to other people.
We hypothesize that cetaceans can communicate their exact experience via visual – holographic images as opposed to humans who can only communicate their impression of their experience through words.