I note that a correspondent in New Scientist for November 13 poses the question whether excessive noise triggers aggressive behaviour. I am quite sure that in fact it does, particularly in certain predisposed individuals. Noise, especially some noise of certain characteristics and above a certain intensity, is a personal stressor, and considering that it prepares people for emergencies and warns them of situations to which they should be alerted, this makes good sense.
In the modern world, however, the role of noise, like that of other social factors, has been confused by excess. The deliberate arousal of the aggressive instinct by powerfully amplified sound, musical and otherwise, is a policy followed in sports stadia, in public demonstrations, in pop festivals and organised "raves". Noise in such circumstances serves to raise activity levels in participants who might otherwise remain passive. It pervades all manner of mass athletic contests, provoking violent behaviour not only from immediate participants but from bystanders as well. In conjunction with a raised blood ethanol concentration, it drives people out of their senses for a time. Politicians and military dictators exploit noise to the full, although it is probably true that silent aggression, if it can be achieved by underhand means, is a far more sinister phenomenon.
Any technique which encourages aggression is questionable from the angle of ethics. Humans are already sufficiently violent towards one another and the world they live in without being encouraged. "The sombre fact is that we are the cruellest and most ruthless species that has ever walked the earth . . .", writes Anthony Storr in his book ‘Human aggression' (1968).
Humans tend to delineate their territories to conform to their assertive drive. You may see this in summer on the popular beaches, where wind-breaks mark the family domain - a sight which is of recent origin, probably promoted by the pressure of population compared with that of a few decades ago. Aggression as such and within limits is not wholly evil. It is the manifestation of a drive towards healthy independence, and part of the growing-up process in a youngster. Apart from being a fundamental protection against predatory attack it is also the basis of intellectual achievement.
Territoriality was originally an instinct which enabled groups of humans to gain a fair share of the basic necessities of life, but it has now gone far beyond reason and merged into a drive to establish superiority in the social order. Individuals contest, even violently, to possess larger cars, smarter houses, more to eat and drink, and louder sources of music. To remain quiet and inoffensive often results in being overlooked and snubbed. My old school motto ran: "In quietness and confidence shall be your strength", and it still appeals to me, despite the criticism that it shows that I am devoid of ambition.
Noise, as I have pointed out, is a stressor, particularly if it is chronic and repetitive, and it surrounds us everywhere today. Living in a noisy neighbourhood does not usually pose a threat unless the noise continues over long periods. Then it induces stress. Travelling by road is a noisy process, and one of its products may be the phenomenon called road rage. Stress may build up from trying working conditions, commuting, and domestic problems, and must be exacerbated by noisy surroundings. Even sedentary behaviour is considered to add to the harmful effects of chronic noise, since it provides no compensatory stimulus. The more we depend on machines as opposed to direct human endeavour, the worse the menace of noise and the more our aggressive behaviour will expand.