Annotation 1 Where the frequency weighting is not specified, A-frequency weighting is commonly understood for sound in air. However, it is good practice to specify the frequency weighting. An appropriate subscript should be added to the symbol; i.e., EA or EC. When no frequency weighting is used, the subscript Z should be used, e.g., EZ.
Annotation 2 The duration of integration should be stated. For the sound exposure measured over a specified time interval such as one hour, a 15-hour day, or a 9-hour night, the duration should be indicated by the abbreviation or letter symbol, for example one-hour sound exposure (1HSE or E1h) for a particular hour; day sound exposure (DSE or Ed) from 0700 to 2200 hours; and night sound exposure (NSE or En) from 0000 to 0700 hours plus from 2200 to 2400 hours.
Annotation 3 Day-night sound exposure (DNSE or Edn) for a 24-hour day is the sum of the day sound exposure and ten times the night sound exposure.
Annotation 4 Unless otherwise stated, the unit for sound exposure is the pascal-squared second.« Back to Standards Terminolgy Index