Digital computation of exchange rates for calculation of noise dosage in embedded systems

Varying noise legislations throughout the world use different techniques for noise dosimetry. One of areas they differ with each other is the use of exchange rates; for instance, the United States Occupational Safety and Health Administration (OSHA) requires the dose to be calculated with an exchange rate of 5dB, whereas some previous regulations have used 4dB and the majority of other international standards use 3dB. As such, workers in a multinational organization may be subject to multiple noise legislations simultaneously. This creates the need for modern personal noise dosimeters to be capable of compliance with multiple regulations in a single measurement, while still being portable and optimised for power and processing. Modern noise dosimeters come with multiple channels which may be set up with a different exchange rate among other settings like threshold values, criterion time etc. These channels usually share the same hardware resources however they may differ in how they actually process data in firmware. This paper explores the effects of varying the integration interval to optimise the processing of exchange rates for noise dosimetry, and its effects on processing for low power, embedded systems. The results are validated against the current dosimetry standards to evaluate their suitability.