A series of tests have been conducted to experimentally show the overall portable air compressor (PAC) noise escalation resulting from the degradation of design features intended to control air and structure‐borne PAC noise. These experiments were designed to determine the potential noise escalation associated with the degradation of each noise abatement feature individually and in combination with the other noise abatement features. Using information generated in the course of the investigation, a time‐dependent correlation has been developed showing the expected overall machine noise escalations associated with typical usage. The potential maximum and minimum noise escalations attained from varying degrees of machine maintenance were similarly determined. Test results have shown that an increase in noise as much as 18.5 dBAcan occur when the prime noise suppression design features of the PAC are degraded. A tape recording will be played to give a subjective appreciation of the level and character of noise escalation from the degradation of various sound control features. [Work supported by EPA.]