An extensive sample of North Carolina industrial audiometric test data has been compiled. The sample includes data from several different types of industrial environments, with the size of the industries represented ranging from less than fifty to over eight thousand employees. The total population considered is in excess of 14000 employees. The data are examined using analytical techniques developed over the past six years while investigating the effectiveness of industrial hearing conservation programs. One of the findings is significant differences in the initial hearing threshold levels by race and sex. A second observation is differences by race and sex in the change in haring levels with time It is concluded that the hearing levels of industrial employees differ significantly by race and sex. The differences are of such magnitude that meaningful evaluations of industrial audiometric data bases are not possible unless the race and sex compositions of the population are considered.