How Dolphins See People
by George Dvorsky  /  12/07/15

“In a world’s first, researchers from the US and UK have created an impression of a submerged human as recorded by a dolphin’s echolocation. To do it, a team led by Jack Kassewitz of used an imaging system known as a Cymascope. The system, developed by John Stuart Reid (who also assisted with the project), made it possible to record and isolate dolphin echolocation sounds directed onto specific objects, and then create 2D images from those sounds. A computer then converted those images into 3D, which allowed the researchers to 3D-print robust, real-world models. “We’ve been working on dolphin communication for more than a decade,” noted Kassewitz in a release. “When we discovered that dolphins not exposed to the echolocation experiment could identify objects from recorded dolphin sounds with 92% accuracy, we began to look for a way for to see what was in those sounds.”

For the experiment, a female dolphin named Amaya directed her sonar beams at a submerged diver, while a hydrophone captured the ensuing echos. To avoid added “noise,” the diver, Jim McDonough, swam without a breathing apparatus to make sure no bubbles would adversely affect the results. As Amaya scanned McDonough with her high frequency sound beam, the CymaScope imprinted sonic vibrations within the water medium. In addition to the diver, the researchers also had Amaya direct her sonar at a flowerpot, a cube, and a plastic “+” symbol.  “We were thrilled by the first successful print of a cube by the brilliant team at 3D Systems,” said Kassewitz. “But seeing the 3D print of a human being left us all speechless. For the first time ever, we may be holding in our hands a glimpse into what cetaceans see with sound. Nearly every experiment is bringing us more images with more detail.”  Looking ahead, the team would like to determine if and how dolphins may be sharing these echolocation images as part of an intra-species sono-pictorial language.”

Dolphin’s Echolocated Impression of a Submerged Human
by Jennifer Viegas  /  Dec 7, 2015

“In a scientific first, researchers have just reproduced what a dolphin saw as it encountered a male diver. This “what the dolphin saw” image of the submerged man reveals that dolphin echolocation results in fairly detailed images. What’s more, it’s now thought that dolphins may share such images with each other as part of a previously unknown marine mammal language. Research team leader Jack Kassewitz of said in a press release that “our recent success has left us all speechless. We now think it is safe to speculate that dolphins may employ a ‘sono-pictorial’ form of language, a language of pictures that they share with each other. If that proves to be true an exciting future lies ahead for inter species communications.”

“CymaScope Professional model with Peltier effect module, integral illumination and interchangeable imaging modules” (2015)

For the research, which took place at the Dolphin Discovery Center in Puerto Aventuras, Mexico, Kassewitz had colleague Jim McDonough submerge himself in front of the female dolphin “Amaya” in a research pool at the center. To avoid bubbles from a breathing apparatus (which might have hurt the later recreation of the image), McDonough wore a weight belt and exhaled most of the air in his lungs to overcome his natural buoyancy before positioning himself against a shelf in the pool. As Amaya directed her echolocation beam to McDonough, high specification audio equipment was used to record the signal. Team members Alex Green and Toni Saul handled that part of the project. Green and Saul then sent the recording to the CymaScope laboratory in the U.K., where yet another colleague, acoustic physics research John Stuart Reid, imprinted the signal onto a water membrane and then computer enhanced the resulting image. “The ability of the CymaScope to capture what-the-dolphin-saw images relates to the quasi-holographic properties of sound and its relationship with water, which will be described in a forthcoming science paper on this subject,” Reid explained.

CymaGlyph of a female elephant. Note very fine structures in upper part of image”

His fellow teammates thought they had captured an echolocation image of McDonough’s face, so that was what Reid was expecting to see. Instead, as he told Kassewitz in a note at the time, the signal translated to “what appears to be the fuzzy silhouette of almost a full man. No face.” As it turns out, Amaya had been echolocating on McDonough from several feet away before she came in closer, so the researchers captured one of those farther away signals. Kassewitz said, “Having demonstrated that the CymaScope can capture what-the-dolphin-saw images, our research infers that dolphins can at least see the full silhouette of an object with their echolocation sound sense, but the fact that we can just make out the weight belt worn by Jim in our what-the-dolphin-saw image suggests that dolphins can see surface features too.” It could be that dolphin echolocation signals result in much clearer, more detailed mental images, and that it’s our technology that isn’t yet fully attuned to what the marine mammals are precisely seeing. As Kassewitz said, “The dolphin has had around fifty million years to evolve its echolocation sense, whereas marine biologists have studied the physiology of cetaceans for only around five decades, and I have worked with John Stuart Reid for barely five years.”

“Examples of square Chladni Figures (drawn by Mary D. Waller)”


“The generic term for the patterns of vibration that occur on the surface of an object when excited by an incident sound is ‘modal phenomena,’ a field of study that covers everything from vibrations in suspension bridges, to vibrations in body parts of cars, to the effects of sound on the human skeleton and internal organs. In the 1970’s this branch of science was named ‘cymatics’ by Swiss doctor Hans Jenny, a word that derives from the Greek ‘kyma,’ meaning ‘wave’ and the inspiration for the name of our CymaScope instrument. The classical view of modal phenomena is that modal patterns form as a consequence of the natural resonant frequencies, or modes, of the object or membrane; current mathematical techniques used to describe this class of phenomena say nothing about the quality of the exciting sound. Musical sounds contain many harmonics so when a circular membrane is excited by a complex musical sound the resulting modal pattern(s) are, naturally, also complex. If we sample a moment from music and analyze it in terms of its fundamental frequency and associated harmonics, and then apply that sample to, say, a circular latex membrane of known elasticity, known diameter and fixed edge, present mathematical techniques cannot predict what pattern will form on the membrane. It appears that no one has attempted to solve this problem, either because no applications for a solution have become evident or because physicists have not seen the importance of mathematically modeling such phenomena. Only the pattern associated with the fundamental frequency can be predicted with any degree of certainty. Thus, for example, the design of musical instruments remains an art rather than a science.

“John Stuart Reid with the first prototype CymaScope” (2002)

Mathematical modelling of the modes of vibration of a circular flexible membrane currently contain only such factors as shape and elacticity of the materials; the mathematics either describe a fixed boundary condition, in the case of a drum, or a single central fixing and a free edge in the case of a circular Chladni plate. Bessel functions and the wave equation are employed to define a finite number of normal modes, based on the natural resonances of the membrane or plate. However, the parameters for the CymaScope are quite different to the case of the drum and the circular resonant plate. Water is free to move at the circular boundary and across its entire surface area. In addition, water responds not only to its normal modes but to any audible frequency imposed on it. In other words, within the limits mentioned above, all the primary periodicities in a given audible sound or in a given sample of music are rendered visible. The resulting patterns can be considered as analogs of the sound or music since the geometry in the resulting patterns is a function of the periodicities within the exciting sound.

“John Stuart Reid making dolphin picture words visible, in collaboration with Jack Kassewitz” (2008)

The CymaScope has applications in almost every branch of science simply because vibration underpins all matter. The ability to see such vibrations permits a depth of study previously unavailable to scientists, engineers and researchers. Readers will have seen our list of research topics covering subject areas from Astrophysics to Zoology. Just as great advances in medical science have come about as the result of the microscope, and huge strides have been made in understanding the Universe with the telescope, the CymaScope instrument holds enormous potential to reveal the hidden realm of sound and vibration. Our team recently made a wonderful breakthrough in the field of dolphin language research and in Mereon research, an energy pattern that may lie at the heart of creation. However, as with all scientific instruments it is vital that the relevant maths is developed, enabling predictions to be made and dynamic systems to be modelled.

If you are a student or professor of applied mathematics we invite you to contact us to discuss a possible collaborative study.”


“Researchers in Key Largo, Florida have audio and spectrographic evidence of a dolphin stunning and disabling her prey with sound. This topic, commonly referred to as The Dolphin Big Bang, has been a hotly debated issue for many years with experts on both sides of the fence. This week Jack Kassewitz of has announced he has photographed and recorded a dolphin named Castaway, actively targeting and stunning a mullet fish. Days later, two researchers from the Marine Mammal Conservancy (MMC) were carefully monitoring Castaway when they witnessed her emitting a powerful blast of sound in the direction of another mullet. That fish showed immediate signs of distress and disorientation. Stacey Anderson, one of the MMC researchers who witnessed the event said “Castaway yelled very loudly at a mullet, the mullet seemed unable to move at first, and then the mullet started swimming on its left side with its head partially out of the water and gulping air. Thirty minutes later, the fish appeared near death when we removed it from the dolphin’s pen.”

Each acoustic event was recorded using high-definition hydrophones in the water, with the data stored digitally onto hard disk recorders. Kassewitz was underwater filming Castaway when the first event took place. He said, “I noticed her sounds and a mullet rapidly retreating from her during the filming, but I didn’t realize what had happened until later when we compared the recorded acoustic signals to the second event, in which the fish was clearly disabled and likely died.” The team is part of a multi-disciplinary research project with MMC and Dolphins Plus assisting Castaway, a stranded, deaf, pregnant offshore bottlenose dolphin (Tursiops truncatus). This pregnant female stranded on November 11, 2006 at Castaway Cove in Vero Beach, Florida and spent 79 days in rehabilitation at Mote Marine Laboratory, recovering enough to be approved for release. An attempt to release her was made on January 30th, 2007. After 3 unsuccessful attempts, including one release into the middle of a pod of dolphins 3+ miles offshore, she was sent to the MMC facility in Key Largo, Florida, for further evaluation and rehabilitation.

“These unique recordings of video and sound have come about because we are monitoring Castaway 24 hours a day, seven days a week for a period of 7-9 months. It seems ironic that a deaf dolphin would teach us so much about this debated topic of whether Dolphins can stun prey,” Kassewitz added. In 2006, the Journal of the Acoustic Society of America, contained a research paper by Kelly J. Benoit-Bird, Whitlow W. Au, Ronald Kastelein that concluded, “Based on the(ir) results, the hypothesis that acoustic signals of odotocetes alone can disorient or “stun” prey cannot be supported (emphasis added).” The recent discovery with Castaway in Key Largo refutes that paper. Kassewitz said in response, “I am sorry that their research has been overturned, but we now know that dolphins can indeed stun their prey.”



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