The Noise Box Test: A Novel Method for Evaluating Sound Absorbers

A novel test method for evaluating sound absorbing materials has been developed. The Noise Box Test makes it possible to study many of the characteristics of an absorber (permeability, thickness, membrane weight, etc.) which affect its performance and, consequently, the manner in which an absorber can best be utilized. This type of test offers certain advantages over existing test methods. The Noise Box is much less expensive than a reverberation room. In comparison to the standing wave tube, the Noise Box Test utilizes a more reasonable sample size and measures performance under conditions of random incidence. The test is believed to be particularly useful for evaluating absorbers for industrial noise control.