Outdoor sound propagation studies by Rich Raspet in the 1980’s

In 1979, Rich Raspet began working at the U.S. Army Construction Engineering Research Laboratory to help mitigate the noise produced by the Army. He and colleagues conducted experiments in sound production by helicopters and explosive charges and experiments in sound propagation at several US and NATO military training installations. His experiences whetted his appetite for the phenomena of shock waves, refraction of sound by wind and temperature gradients, reflection of sound by porous ground impedance, diffraction by turbulence, and much more, joining the National Center for Physical Acoustics in 1987. Results from one of his experiments started this presenter on a similar journey.