sound exposure

2.62  sound exposure. Time integral of the square of an instantaneous frequency-weighted sound pressure signal. Unit, pascal-squared second; symbol, E, abbreviation, SE.

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., E_A or E_C. When no frequency weighting is used, the subscript Z should be used, e.g., E_Z.

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 E_1h) for a particular hour; day sound exposure (DSE or E_d) from 0700 to 2200 hours; and night sound exposure (NSE or E_n) from 0000 to 0700 hours plus from 2200 to 2400 hours.

Annotation 3          Day-night sound exposure (DNSE or E_dn) 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.