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- Körning-Ljungberg, Jessica, et al.
(författare)
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Effects on spatial skills after exposure to low frequency noise
- 2004
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Ingår i: Journal of Low Frequency Noise Vibration and Active Control. - : SAGE Publications. - 0263-0923 .- 1461-3484 .- 2048-4046. ; 23:1, s. 1-6
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Tidskriftsartikel (refereegranskat)abstract
- A study of spatial skills was conducted with 27 male and 27 female participants. The aim of the study was to examine the post-exposure effect of a complex low frequency noise (21 Hz) on a mental rotation task. It was hypothesised that reaction time and number of errors would increase after 20 minutes exposure to noise exposure compared to performance after a control condition, and that groups exposed to higher intensity noise would exhibit greater impairment. Three groups of participants were exposed to a control condition and a noise condition (either, 77, 81 or 86 dB (A)). After each exposure, subjects completed a mental rotation task where the stimulus consisted of one of three letters presented in five different rotations, showed either normally or mirrored. The participants were asked to respond as quickly and accurately as possible, affirmatively if the letter presented was not mirrored and negatively if it was mirrored. Statistical analysis revealed that the medium intensity level generated significant post-exposure effects while no effects were seen at the low or high intensity levels
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- Lundquist, Pär, 1973-, et al.
(författare)
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Low frequency noise and annoyance in classroom
- 2000
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Ingår i: Journal of Low Frequency Noise Vibration and Active Control. - London : Multi-Science Publishing. - 0263-0923 .- 1461-3484 .- 2048-4046. ; 19:4, s. 175-181
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Tidskriftsartikel (refereegranskat)abstract
- The most common method for noise assessment is the A-weighted sound pressure level. The question has been raised as to whether the frequency weighting with an A-filter gives a correct result when assessing the annoyance response to noise containing strong low frequency noise (LFN) components. One method suggested to identify LFN is the dB(C) – dB(A) difference. The aims of this study are to investigate if background noise in Swedish elementary schools is to be considered as LFN, further to test the hypothesis that students exposed to audible LFN at high levels are more annoyed than students exposed to LFN at lower levels. The results indicate that the noise in 16 out of 22 classrooms should be considered as LFN. The analysis did not show any difference in rated annoyance between students exposed to high LFN levels and students exposed to low LFN levels.
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