Tilahun Adera
Dept. of Preventive Medicine, Medical College of Virginia, 1008 East Clay St., Box 980212, Richmond, VA 23298
The concept of an audiometric database analysis (ADBA) method for evaluating the effectiveness of hearing conservation programs has been appearing in the scientific literature for more than 15 years. This concept was recently developed into a series of procedures and is currently being considered for acceptance as a U.S. National Standard (ANSI S12.13-1991). Although the method presents the various analytical procedures in a narrative fashion, mathematical formulas expressing the essential principles have not been provided. In addition, there currently is no method for determining the overall effectiveness of a hearing conservation program (HCP) following application of ADBA procedures to a set of audiometric data. This paper provides the mathematical formulas for four ADBA procedures including the percent worse sequential, percent better or worse sequential, standard deviation applied to single test frequencies, and standard deviation applied to averages of test frequencies. In addition, the paper introduces and illustrates two methods of summarizing results from ADBA procedures, which includes the standard score estimator and the score designator. Each of these methods consists of at least a median and a mean-based procedure. The strengths and limitations of these procedures in determining the overall effectiveness of an HCP are discussed.