Subjective annoyance caused by indoor low-level and low frequency
noise and control method
Journal of Environmental Sciences, (2005)Abstract
The influence of low-level noise has not been widely noticed. This
paper discovered that low-level and low frequency noise (A-weighted
equivalent level Leq < 45 dB) causes higher probability of subjective
annoyance. The fuzzy mathematic principle was applied to deal with
the threshold level of subjective annoyance from noise in this study;
there is preferable relationship between the indoor noise and noise
annoyance at low frequency noise level. Study indicated at the same
centered noise level, the change of annoyance probability is mainly
caused by the change of the frequency spectrum characteristic of
the indoor noise. Under low noise level environment, without change
of the medium-low frequency noise, the slight increase of medium-high
frequency noise level with the help of noise sheltering effect can
significantly reduce the noise annoyance. This discovery brings a
new resolution on how to improve the environmental quality of working
or living places. A noise control model is given in this study according
to the acoustic analysis.