This is a demonstration of the interference pattern created by two speakers playing the same 2000 Hz tone. It is carried out by moving a microphone through the sound field and noting that the sound is louder in some spots (those with constructive interference) than others.
This demonstration was created at Utah State University by Professor Boyd F. Edwards, assisted by James Coburn (demonstration specialist), David Evans (videography), and Rebecca Whitney (closed captions), with support from Jan Sojka, Physics Department Head, and Robert Wagner, Executive Vice Provost and Dean of Academic and Instructional Services.