DJ Dolphin Z: How Dolphins Can Improve on Cochlear Implants
DJ Dolphin-Z with the perfect beat. If dolphins could actually do human-style DJ’ing with turntables, mixers, samplers, and drum machines, they might paint something that looks like 3D sound “pictures” of their moods, feelings, and surroundings. Dolphins, along with bats, are two of the most well-known users of echolocation, employing high-frequency sounds to locate prey, find their way, or to communicate. Studies show dolphins and bats evolved nearly the exact same molecular means for hearing at high frequencies. Perhaps if there was a DJ Dolphin-Z, he might spin the following tune on echolocation (courtesy of Batney Ears, Habitat Records):
New research coordinated by Professor Robert Allen from the University of Southampton on how dolphins and bats use sound echolocation could soon help people with cochlear implants listen in stereo. The project, known as B.I.A.S. (Biologically Inspired Acoustic Systems), includes researchers from NERC British Geological Survey, the Universities of Edinburgh, Leeds, Leicester, Southampton, and Strathclyde, and Fortkey Ltd. Signal and Image Processing. They plan to develop sonar systems “to harness the acoustic capabilities of biological systems and use these in a range of practical engineering applications.”
Cochlear implants, of course, are electronic devices surgically implanted under the skin behind the ear that restore partial hearing to the deaf. The implants bypass damaged hair cells and convert speech and environmental sounds into electrical signals and send these signals to the hearing nerve. Here’s an animated video explaining how cochlear implants work using the well-known Nucleus Freedom device:
As reported by BBC News, B.I.A.S. researchers are also looking at developing ultrasonic transducers that can be used in small robotic vehicles to help them navigate in tight spaces that might be too dangerous for humans. “We’re currently looking to apply these methods to positioning of robotic vehicles, which are used for structural testing,” says Simon Whiteley from the University of Strathclyde. A recently published study of bat echolocation in Bioinspiration & Biomimetics concludes that “the ability to record and accurately synthesize echolocation calls enables the exploitation of biological signals in human engineering systems for sonar, materials characterization and imaging.” Specifically, Dr. Whiteley and his colleagues found that overlapping signals let bats spot objects that are smaller than the wavelengths of the sounds they emit. This fundamental research can be used to improve the resolution of sound-based imaging systems.
Dolphins are capable of discriminating different materials based on acoustic energy and can out-perform existing human technology.
Dolphins are capable of discriminating different materials based on acoustic energy and can out-perform existing human technology. Excellent at detecting and discriminating between objects, they also can also focus acoustic energy when both transmitting and receiving. Using 2D/3D bioacoustical modeling, measurements of the acoustic field of echolocating dolphins demonstrate that they emit a rapid series of pulses in a narrowly focused beam that emanates from the forehead and rostrum. This echolocation creates a 3D “picture” of sound. Such acoustical sound imaging has been used by researchers from the University of Bristol to develop powerful real-time image processing and software algorithms to help blind people identify objects and obstacles, such as trees, street furniture, vehicles and other people. Their system uses stereo images to create a “depth map” for calculating distances. It also analyzes moving objects and predicts where they are going. A blind person can actually wear headphones and hear how sounds change as they move around. The stereo audio system makes it possible to place sounds so that the brain can interpret them as a point in space. Sounds get louder as you walk towards objects, and quieter as you move away.
It must be very cool to be DJ Dolphin-Z or one his bat cousins and to “see” the world in 3D sound pictures. How must the world appear to a nearly weightless dolphin suspended in water with 360-degree perception based on echolocation, or a bat zeroing in on an insect victim in the dark? Much of what we are learning from our biological brethren is rapidly being incorporated into technological advances. Perhaps someday we may actually be able to see the world in 3D sound pictures through the echolocating “eyes” of a dolphin.