ABSTRACT
In this chapter we are primarily concerned with the effects of noise, especially loud noise, on human performance. Investigations of the effects of noise on behaviour have been conducted for several decades, beginning during the First World War, and there is now a substantial literature on noise effects both in laboratory situations, and in field settings such as the classroom and the workplace. Noise may be detrimental to performance for several reasons. First, it disrupts auditory perception. Exposure to high noise levels can impair hearing and make spoken communication difficult, if not impossible, to achieve (Ainsworth, 1985; Davies & Jones, 1982; Tempest, 1985). Second, the irrelevant information delivered by noisy environments may affect post-perceptual processing, perhaps reducing attentional resource availability or forcing greater selectivity of attention. Research conducted in the past 20 years or so shows that irrelevant speech of normal intensities influences performance of certain tasks (see Jones & Morris, 1992). Such distraction effects appear to have considerable practical and theoretical importance. Third, noise may have stress-related effects that are distinct from the more direct effects of noise on auditory information processing. Noise may produce feelings of irritation and annoyance (Langdon, 1985), although there are marked individual differences in annoyance to specific noise sources (see Jones & Davies, 1984), and bring about changes in physiological state (Davies, 1968a, 1976). Noise is often defined as “unwanted sound”, a definition that emphasises the role of emotional factors in response to noise.
