Monitoring the hearing of persons who routinely work in potentially hazardous noise areas serves to identify changes, or shifts, in hearing that may be attributed to excessive exposures. Since October 1956 (21 years) medical personnel of the US Air Force have used threshold shifts (current annual audiogram compared against individual reference) to identify persons who may be acquiring a sensorineural loss of hearing due to noise. Fortunately, this procedure has proven of extreme value since it identifies the occurrence of a noise‐induced hearing loss during the earliest stages and thus, when combined with proper medical management, prevents the occurrence of significant amounts of hearing loss in the speechhearing range. The authors describe the results of a study of the relative effectiveness of 22 different criteria (or methods) that could be used to identify shifts in hearing (significant threshold shifts, STS) that may be attributed to excessive noise. A total of 56,678 military and civilian employees was selected for this study. The proportions of the total sample that would be identified using the different STS criteria are given; proportions ranged from 7.18% to 65.19%. Median hearing level for the total sample, as well as hearing levels for each of the groups identified by the 22 STS criteria are also reported.