June 30th, 2011 by J.H. Soeder

This is the listening device built by Stanford University, based on orca ears. CREDIT: Onur Kilic
It’s an amazing new discovery – and invention – that has been achieved thanks to whales.
In a story I found in TechNews Daily, a team of scientists have developed an underwater listening device basic on the ears of killer whales.
“The decibel range of the sensor ranges from 20 decibels to 180 decibels in water — this is equivalent to a microphone that can record a whisper in a quiet library and the sound from 1 ton of TNT exploding 60 feet away,” researcher Onur Kilic, an applied physicist at Stanford University, told TechNewsDaily.
“At the same time, this new hydrophone can work at virtually any depth, no matter how crushing the pressure. It also can hear sound frequencies from 1 hertz to 100 kilohertz, spanning pitches far higher than the whine of a mosquito and far lower than a foghorn.”
The benefit of this invention will allow scientists to track whales underwater and the equipment will be able to track and hear other sounds in the water, such a leaking oil from an underwater pipeline.
The device has the capability of also filtering out other sounds. Killer Whales do this naturally, when they are hunting other sea creatures, including whales. And so the same theory applies.
Since whales live in the water, their ears – and ear drums use water fluids.
“The only way to make a sensor that can detect very small fluctuations in pressure against such immense range in background pressure is to fill the sensor with water,” Kilic said. Doing so keeps the water pressure on each side of the membrane equal, no matter how deep.
“Kilic and his colleagues fabricated a microchip with a silicon membrane about 500 nanometers thick, or about 25 times thinner than common plastic wrap. They next drilled a grid of tiny holes in the membrane to allow water to pass in and out.
“To detect the wobbles of such a membrane in response to sound, the researchers shine a laser on this reflective sheet with a fiber-optic cable. Since the diameter of the holes in the membrane are close to the wavelength of light from the laser, the holes interfere with the light trying to pass through the membrane, reflecting it toward a detector. When the membrane gets deformed by sound waves, the intensity of the light alters, which the detector can pick up.
“The kind of displacements you get off the diaphragm for the quietest sounds in the ocean is on the order of a hundred-thousandth of a nanometer,” Kilic said. “That is 10,000 times smaller than the diameter of an atom.”
The point is, scientists are using something whales have developed over millions of years. Our in depth studies of them have only actually begun in earnest the last fifty years or less. Yet here is a breakthrough that has a definite value to man, yet we still allow whales to be hunted and killed.
Does that make sense?
Although man has his own set of ears, is he really listening?