Laboratory study on the effects of office noise on mental performance

The effect of noise on human activities and, in particular, on working performance may be investigated in different ways. Generally, questionnaires are the preferred means to collect subjective sensations of annoyance and satisfaction. However, as any other subjective rating, they may be significantly biased by memory effects as well as by other non-environmental variables. So, in order to define a better way of describing the annoyance due to noise, a laboratory study was carried out based on the measurement of mental performance by means of Stroop and memory tests. Different noise excerpts having different levels were recorded using binaural microphones. The excerpts were then binaurally played back (at the same level) through headphones while subjects carried out the test. A careful procedure was followed in order to avoid (or at least limit) any training effect. The same subjects also performed the test under quiet conditions in order to define their "reference" performance. The effect that different kind of noise had on the mental performance was finally estimated by comparing the results of the tests obtained with noise with those obtained in quiet conditions.