Leventhall, G. Effects on Performance Due to LFN (Sick Building Syndrome)
Effects on performance and work quality due to Low Frequency Ventilation Noise
K. Persson Waye, R. Rylander, S. Benton, H.G. Leventhall, 1997
Journal of Sound and Vibration
A pilot study was carried out to assess method evaluating effects of low frequency noise on performance. Of special interest was to study objective and subjective effects over time. Two ventilation noises were used, one of a predominantly mid frequency character and the other of a predominantly low frequency character. Both had an NC value of 35. For the study 50 students were recruited and 29 selected on the basis of subjective reports of pressure on the eardrum after exposure to a low frequency noise. Of these 14 randomly selected subjects aged 21 to 34 took part. The subjects performed three computerized cognitive tests in the mid frequency or the low frequency noise condition alternatively. Tests I and II were performed together with a secondary task.
Questionnaires were used to evaluate subjective symptoms, effects on mood and estimated interference with the test results due to temperature, light and noise. The results showed that the subjective estimations of noise interference with performance were higher for the low frequency noise (p < 0.05). The exposure to low frequency noise resulted in lower social orientation (p < 0.05) (more disagreeable, less co-operative, helpful) and a tendency to lower pleasantness (p = 0.07) (more bothered, less content) as compared to the mid frequency noise exposure.
Data from test III may indicate that the response time during the last part of the test was longer in the low frequency noise exposure. The effects seemed to appear over time. The hypothesis that cognitive demands are less well coped with under the low frequency noise condition needs to be further studied. The results further indicate that the NC curves do not fully assess the negative effects of low frequency noise on work performance.