  A lot of research has been carried out to find out the influence of low
frequency noise on human behavior. Based on currently available results, some
countries have been developing National Standard to limit the low frequency
noise to protect people's health and working performance. However, after
investigating 28 National Standards about noise limitation of working machine
and other noise emission standards of China, it is found that the stipulation
of low frequency noise covers limited aspects. Most of the limitation used
A-weight sound level as the evaluation index, which only presents the loudness
perception of sound, not its influence. In this paper, two connected topics are
presented. One is to investigate the Chinese National Standard and
International Standard, in order to summarize all the noise limitation on low
frequency noise. The second topic is the application of online psychoacoustic
test to evaluate the influence of low frequency noise on human performance,
which can enlarge the subjective testing sample size in order to facilitate the
establishment of related National Standard. The online Hass effect experiment
is repeated to verify the accuracy of online psychoacoustic test. The
volunteers are asked to conduct several sessions of the colour identification
problems under different kind of controlled noise. The accuracy and finishing
time are taken into consideration to evaluate their performance under different
kinds of noise. The results show that low frequency noise does affect humans'
working performance and the existing Chinese Noise limitation Standards are
inadequate in low frequency noise limitation.
