Audiometry is the measurement of individuals’ hearing sensitivity using finely-regulated sound inputs.  It is a crucial component of a hearing loss prevention program (HLPP) with an emphasis on the range of frequencies prevalent in speech communication.  To be valid, audiometric testing must be conducted under controlled conditions and the results interpreted by a knowledgeable technician or audiologist.
     This installment of the “Occupational Soundscapes” series provides an introduction to audiometry, requirements for equipment, facilities, and personnel involved in audiometric testing, and the presentation and interpretation of test results.  It targets, primarily, those enrolled in – as opposed to responsible for – an HLPP.  Its purpose is to develop a basic understanding of a critical component of hearing conservation efforts to, in turn, engender confidence in the administration of procedures that may be foreign to many who undergo them.

     Occupational soundscapes, as outlined in Part 1, are comprised of many sounds.  Each has a unique source and set of defining characteristics.  For some purposes, treating all sounds in combination may be appropriate.  For others, the ability to isolate sounds is integral to the purpose of measuring sound levels.
     Of particular importance to a hearing loss prevention program (HLPP) is the ability to add, subtract, and average contributions to the sound pressure level (LP, SPL) in a workplace.  The ratios and logarithms used to calculate SPLs, presented in Part 3, complicate the arithmetic, but only moderately.  This installment of the “Occupational Soundscapes” series introduces the mathematics of sound, enabling readers to evaluate multiple sound sources present in workers’ environs.