Acoustic Change Detection Using Sources of Opportunity

Report No. ARL-TN-0454
Authors: Owen R. Wolfe and Geoffrey H. Goldman
Date/Pages: September 2011; 18 pages
Abstract: There is interest in developing low-cost, low-power non-line-of-sight sensors for monitoring human activity. This report describes an algorithm that can detect a physical change in a building such as a door opening or closing. The algorithm is based on cross-correlating the acoustic signal measured from two microphones. Detection occurs when a statistically significant change in normalized cross-correlation is measured at different times. The algorithm was tested with an experiment that used a simple, inexpensive, hand-held FM radio as a sound source, two microphones, and a data acquisition system. The algorithm successfully detected a change in the environment when a door was opened or closed.
Distribution: Approved for public release
  Download Report ( 0.685 MBytes )
If you are visually impaired or need a physical copy of this report, please visit and contact DTIC.

Last Update / Reviewed: September 1, 2011