The talk "Acoustical rediscovery of right whales in a former whaling area, the Cape Farewell Ground, between Greenland and Iceland" (3aAB9) is at 10:45 a.m. on Wednesday, May 20. Abstract: http://asa.aip.org/web2/asa/abstracts/search.may09/asa583.html
13) CLOGGED PIPES MAKE A SPECIAL SOUND
One way to find a clog under a sink is to take on the dirty job of dismantling the pipes. Now mathematician Alex Tolstoy, of ATolstoy Sciences in the United States, and colleagues at the University of Bradford in the United Kingdom have developed a cleaner way that hears where a blockage is located, using a technique pioneered in underwater acoustics. With further development, the method could be used to remotely track down problems in unpleasant areas like sewer lines.
The group built a device that -- like the echolocation used by bats and dolphins -- sends out high-pitched frequencies and listens to the sounds that bounce back. The listening device first records the profile of reflected sound coming back from an empty pipe. When the pipe is blocked, this sound profile changes. Using a signal-processing technique called matched-field processing, Tolstoy picks out the more important changes and calculates how long these frequencies took to bounce back to the two micr
|Contact: Jason Bardi|
American Institute of Physics