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EFFECTS ON HEALTH
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people most objected to barking dogs, banging doors, noise from radio, television,
or hi-fi and human voices (Grimwood, 1993). In this survey, two types of emotional
response to noise were observed: outwardly directed aggression, characterized by
feelings of annoyance, aggravation, bitterness and anger towards the source of the
noise, and a more emotional response of tension, anxiety and feelings of pressure.
These responses are reminiscent of the distinction between internalizing and externalizing
disorders. Whether noise from neighbours can induce psychiatric disorder
has been little studied in community research, but this is an area that deserves further
study (Stansfeld, Haines and Brown, 2000).
Undoubtedly, prolonged exposure to noise can be very upsetting, intrusive and interfering
for sleep and everyday activities. In poorly built dwellings, especially apartments,
even low intensity noises may be clearly audible through walls, floors, or ceilings
(Raw and Oseland, 1991). In this situation, noise is destructive of privacy, especially
for those living alone, and may be associated with perceptions of threat or
increase a sense of isolation. This may be especially the case among people who are
chronically anxious and likely to complain of sensitivity to noise; prolonged noise
exposure may make them more anxious and unhappy. Often, this leads to arguments
with neighbours, leading to a breakdown of neighbourly relationships and further
isolation which may well in itself have a bad effect on mental health. Occasionally,
this may be a sign of feelings of persecution associated with psychotic illness in
which noise exposure is just an external trigger of an internally generated condition.
4.8.6 MECHANISMS FOR CAUSAL LINKS BETWEEN NOISE
AND MENTAL HEALTH
What might the mechanism be for the effects of noise on mental health? One way to
approach this is through the effects of noise on cognitive performance where the laboratory
evidence of effects is fairly robust (Smith and Broadbent, 1992). Effects of
noise on mental health might be expected because there is evidence that noise
impairs other aspects of human functioning, such as performance (Loeb, 1986) and
sleep, that are important in maintaining normal functioning, and that noise causes
adverse emotional reactions such as annoyance. In general, it seems that noise exposure
increases arousal, and decreases attention through distraction (Broadbent,
1953), increases the need for focusing attention to cut out irrelevant stimuli (Cohen
and Spacapan, 1978), as well as altering choice of task strategy (Smith and
Broadbent, 1981). Even relatively low levels of noise may have subtle ill effects, and
in this respect, the state of the person at the time of performance may be as important
as the noise itself (Broadbent, 1983). Individuals’ perception of their degree of
control over noise may also influence whether it impairs memory (Willner and
Neiva, 1986) while perception of lack of control over environmental conditions may
be an important mediator of health effects.
Additionally, noise may also affect social performance as: (1) a stressor causing
unwanted aversive changes in affective state; (2) by masking speech and impairing
communication; and (3) by distracting attention from relevant cues in the immediate
social environment (Jones, Chapman and Auburn, 1981). It may be that people
whose performance strategies are already limited for other reasons (for instance
through high anxiety) and who are faced with multiple tasks may be more vulnerable
to the masking and distracting effects of noise.
The mechanism for the effects of noise on health is generally conceptualized as fit-
NIGHT NOISE GUIDELINES FOR EUROPE