Other factors that correlate with sound annoyance are increased absence form work,[3] sleep disturbance,[3] and interference with performing cognitive tasks like paying attention at school.
Psychoacoustic analysis reveals that sound pressure level is a less than ideal predictor of human reception of noise, so efforts have been made since the 1960s[6][7] to apply loudness metrics instead, which can incorporate other factors such as spectral and temporal auditory masking and level-dependent frequency weighting to more accurately track human reception.
Integration of individual sounds into an auditory or dose estimate has traditionally followed an extension of Stevens's power law which applies simple power or energy summation such that a sound lasting twice as long is considered of equal impact as one 3 dB higher in amplitude.
More recent work such as Moore and Glasberg on time-varying loudness[8] and Nordtest NT ACOU 112[9] has examined a more detailed understanding of other factors such as onset rate and masking.
[11] An interim threshold of 55 dB Lnight is set as an upper bound, because above this limit, (sleeping) disorders are more prevalent.
In the Netherlands the government set up laws to protect households and other noise-sensitive buildings like hospitals and schools from noise pollution.
When this system exceeds the lower bound nonetheless, a municipal exemption can be given when appealed to the interim "urban and environmental approach".