Parabolic Mic in SAR

In 2015 Nat Bowditch and two others from the team responded to a mutual aid call for a lost hunter in the Iron Lakes region of Madera County. After a day of searching by six teams yielded no signs of the hunter, Nat and the team stood on a ridge at dusk calling for him. At that moment Nat wondered whether a parabolic microphone, commonly used to capture sound in broadcast football games, would allow him to better hear a response form the subject. Fortunately, the hunter did hear the calls and hiked up to the ridge.

After some preliminary tests, the Santa Clara team conducted a rigorous study comparing the parabolic microphone to unaided hearing in detecting and understanding hidden callers at distances from 300 to 2500 meters. The study showed that in favorable conditions, unaided hearing allows a person to hear and understand a caller out to 1200 meters. The parabolic microphone extended this to 2500 meters. The study was published in the Journal of Wilderness and Environmental Medicine. The study, and a video about the parabolic microphone, are on the Santa Clara Sheriff’s Search & Rescue website http://www.sccssar.org/specialty/parabolic/ Readers of the study are warned not to read the statistical methods section before operating heavy machinery.

The course will very briefly cover the results of the study and how to use the parabolic microphone on a search. But the best way to understand its capabilities is to strap it on and try to hear a distant caller. Everyone will get a chance to do this.

Instructor Nat Bowditch

Nate Bowditch has been a volunteer with the Santa Clara County Sheriff’s Search & Rescue team since 2004. Nat has been on more than 100 searches. He holds degrees from Cornell, Stanford and the University of Chicago, but is not smart enough to recognize poison oak in the field.