Seeing is Believing - A Better Way to Diagnose Noise Sources

This paper describes a method of noise diagnostics by visualizing sound at its source and as it propagates through a complex structure. The underlying principle of this approach is the Helmholtz equation least squares (HELS) method which has been proven theoretically and experimentally to be a robust tool for reconstructing acoustic radiation from an arbitrary object. Examples of using HELS to pinpoint the noise source locations and their transmission paths are demonstrated. The depth, breadth, and clarity of the information retrieved can be very helpful to a practicing engineer who is challenged to recommend abate noise problems cost effectively.