EFFECTS ON PERFORMANCE AND WORK QUALITY DUE TO LOW-FREQUENCY VENTILATION NOISE

A pilot study was carried out to assess method evaluating effects of l ow frequency noise on performance. Of special interest was to study ob jective 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. F or the study, 50 students were recruited and 30 selected on the basis of subjective reports of pressure on the eardrum after exposure to a l ow frequency noise. Of these, 14 randomly selected subjects aged 21 to 34 took part. The subjects performed three computerized cognitive tes ts in the mid frequency or the low frequency noise condition alternati vely. Tests I and II were performed together with a secondary task. Qu estionnaires were used to evaluate subjective symptoms, effects on moo d and estimated interference with the test results due to temperature, light and noise. The results showed that the subjective estimations o f noise interference with performance were higher for the low frequenc y noise (p < 0.05). The exposure to low frequency noise resulted in lo wer social orientation (p < 0.05) (more disagreeable, less co-operativ e, helpful) and a tendency to lower pleasantness (p = 0.07) (more both ered, less content) as compared to the mid frequency noise exposure. D ata 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 e ffects seemed to appear over time. The hypothesis that cognitive deman ds are less well coped with under the low frequency noise condition, n eeds to be further studied. The results further indicate that the NC c urves do not fully assess the negative effects of low frequency noise on work performance. (C) 1997 Academic Press Limited.