Time and frequency weightings and the assessment of sound exposure

Since the development of averaging/integrating sound level meters and frequency weighting networks in the 1950’s, measurement of the physical characteristics of sound has not changed a great deal. Advances have occurred in how the measured values are used (day-night averages, limit and action values, etc.), but in essence the measurement principle remains the same. There are advantages of having a well established, world-wide methodology, such as: uniformity of measurements, wide variety of measurement equipment, experience based
knowledge, etc. The problem arises from the ambiguity of the measure, where a wide variety of sound characteristics that have different effects on the hearing lead to the same result. Today, the technological advances permit precise measurements of the time and frequency characteristics of sound, which can be stored and analyzed to give a better description of the exposure. This information is being used to investigate metrics that can differentiate temporal
characteristics (impulsive, fluctuating) as well as frequency characteristics (narrow-band or tonal dominance) of sound exposures. This presentation gives an overview of the existing sound measurement and analysis methods,
that can provide a better representation of the effects of sound exposures on the hearing system