Expendable microphones may help locate building collapse survivors
Data gathered by Penn State engineers in a volunteer effort at the World Trade Center tragedy, suggests that simple, inexpensive microphones dropped into the rubble of a collapsed building may be able to aid search and rescue teams despite ground level noise.
Dr. Thomas B. Gabrielson, associate professor of acoustics and senior research associate at Penn State’s Applied Research Laboratory, says, “In conventional survivor searches, noise generating activities at the surface must be stopped while listening for survivors.”
However, the Penn State team found that the noise level in the interior voids of the rubble was about the same as that of a quiet residential neighborhood even though the noise level at the surface was much higher due to constant operation of three heavy lift cranes, air hammers, and dozens of rescuers workers.