Does low frequenca noise at moderate levels influence human mental
performance
Journal of low frequency noise, vibration and active control, (2005)Abstract
The aim of this study was to assess the influence of low frequency
noise (LFN) at levels normally occurring in the industrial control
rooms on human mental performance (attention, visual perception and
logical reasoning) and subjective well-being.Subjects were 191 male
volunteers categorised in terms of subjective sensitivity to noise
in general. They performed standardised tests: the Signal Detection
Test (test I), the Stroop Colour-Word Test (test II), and two sub-tests
of the General Aptitude Test Battery, i.e. the Math Reasoning Test
(test III) and the Comparing of Names Test (test IV). Three different
acoustic conditions were used in the between-subjects design: the
background laboratory noise of about 30 dB(A), LFN, and a broadband
noise without dominant low frequency components (reference noise)
at 50 dB(A). Each subject was tested only once in randomassigned
exposure conditions.Generally, no significant differences in performance
related to exposure conditions were noted. Some of the results from
test I and test II were influenced by sensitivity to noise. However,
there were no significant differences between high- and low-sensitive
subjects during exposure to LFN.The annoyance of LFN and reference
noise was rated higher than that of the background noise. Subjects
highly-sensitive to noise reported higher annoyance due to LFN in
comparison with low-sensitives. No significant differences related
to noise sensitivity in annoyance assessment of background and reference
noises were noted.In conclusion, no effects due to LFN on mental
performance compared to background and reference noises were found.