This provision is a "subjective immission" control with a curfew. It is for impulsive sound sources that are not associated with construction activities or shooting ranges. Many communities use the Maximum Permissible Sound Levels criterion (see below), with a correction for the character of the sound. Illinois () sets maximum blasting levels by land use zone and in three time categories. Portland, OR (Section 18.10.010.F) limits levels to 100 dB (peak) from 7am to 10pm and 80 dB (peak) from 10pm to 7 am.