Lesson 25 Non-auditory effects of noise
Many people in industry and the Services, who have practical experience of
noise, regard any investigation of this question as a waste of time; they are not
prepared even to admit the possibility that noise affects people. On the other
hand, those who dislike noise will sometimes use most inadequate evidence to
support their pleas for a quieter society. This is a pity, because noise abatement
really is a good cause. and it is likely to be discredited if it gets to be associated
with bad science.
One allegation often made is that noise produces mental illness. A recent article
in a weekly newspaper, for instance, was headed with a striking illustration of a
lady in a state of considerable distress, with the caption 'She was yet another
victim, reduced to a screaming wreck '. On turning eagerly to the text, one learns
that the lady was a typist who found the sound of office typewriters worried her
more and more until eventually she had to go into a mental hospital. Now the
snag in this sort of anecdote is of course that one cannot distinguish cause and
effect. Was the noise a cause of the illness, or were the complaints about noise
merely a symptom? Another patient might equally well complain that her neighbours
were combining to slander her and persecute her, and yet one might be
cautious about believing this statement.
What is needed in the case of noise is a study of large numbers of people living
under noisy conditions, to discover whether they are mentally ill more often than
other people are. The United States Navy, for instance, recently examined a very
large number of men working on aircraft carriers: the study was known as
Project Anehin. It can be unpleasant to live even several miles from an aerodrome;
if you think what it must be like to share the deck of a ship with several squadrons
of jet aircraft, you will realize that a modern navy is a good place to study
noise. But neither psychiatric interviews nor objective tests were able to show
any effects upon these American sailors. This result merely confirms earlier
American and British studies: if there is any effect of noise upon mental health
it must be so small that present methods of psychiatric diagnosis cannot find it.
That does not prove that it does not exist; but it does mean that noise is less
dangerous than, say, being brought up in an orphanages--which really is a mental
health hazard.