Why we need silence
What too much noise does to us — and how quietness can help
A
AExcessive noise has lately been labelled an ‘underestimated threat’ to public health by a leading international health agency, which warns that residents of cities like Delhi, Cairo and São Paulo endure night-time noise well above the 40 decibels it recommends. Widespread and persistent, the problem is by no means confined to such places: one European study estimated that close to a quarter of the continent’s population is regularly subjected to levels reckoned harmful. As Diego Castellano, an acoustics consultant who helped shape several national noise standards, puts it, the brain has no ‘earlids’ with which to shut unwanted sound out, whether we happen to be awake or asleep.
B
BThere are sound evolutionary reasons why we are so sensitive to sound. Noises carry information that once helped our ancestors find their way and steer clear of threats, and the body is built so that a sudden or loud one is never ignored: on hearing it, we undergo an automatic chemical shift. The heart drives blood pressure upward, the muscles tighten, and hormones pour out to ready us to fight or flee — all of it useful in the moment. Sustained exposure is another matter. Over months and years that same alarm response has been tied to a range of complaints, running from broken sleep to disorders of the heart and circulation.
C
CLuka Boone, who researches psychotherapy, accepts that silence does not suit everyone — least of all those already wound up by stress. ‘Someone in that state often cannot settle or unwind in a silent setting,’ he notes, adding that a guide can help such people ease into silence by degrees until its rewards begin to show. All the same, Boone is sure that silence is far easier to come by in ordinary life than most of us assume. For one thing, it need not be total: in a study of his, people who sat outdoors in a quiet garden reported feeling noticeably calmer and less bored than others who were left alone in a room of complete silence. For another, a little goes a long way. ‘Hours of it are not the point,’ he says. ‘Short spells of quiet, taken often, do more good than one long stretch once a week. Simply tracking down the corners of your day where a bit of silence is available can make a real difference.’
D
DThe neuroscientist Petra Ansell likewise champions silence as a form of treatment. ‘Finding ways to grow quiet calms not merely our surroundings but something within us,’ she says. ‘With that inner stillness we take in more of our situation, and sense what a given moment asks of us, so that our response can be a fitting one.’ Silence, she cautions, does not reward everyone equally, and the decisive factor is desire: the person has to genuinely wish to take part. ‘Studies of animals and of people alike show that willingness and intent matter,’ Ansell observes. ‘Forced on someone who does not want it, silence can be deeply distressing rather than restful.’
E
EScientists are equally keen to pin down which features of silence do us the most good. Among the most closely studied is the flotation tank — a sealed pod of heavily salted water, sound- and light-proof, in which the body floats in deep repose. A few floaters report their senses playing tricks, a faint humming or flickers of light, but these are harmless and take nothing away from the experience, says the clinical neuropsychologist Nadia Dupont. ‘Deprived of input from outside, the mind sets about filling the void it perceives, trying to make sense of the dark, silent space,’ she explains — so vividly that some floaters catch the sound of their own eyelids closing. What ushers people into calm or meditation, though, is the chance to fix their attention on the slow, steady rhythm of the breath.
F
FTo test the tanks as therapy, Dupont’s group enrolled 50 volunteers troubled by stress and its associated complaints, asking each to complete a survey both shortly before and shortly after a single hour-long float. Once the hour was up, they described less pain, looser muscles and milder symptoms, along with a greater sense of calm and a general lift in their mood. How sensory deprivation acts on the brain itself is harder to say. For a closer look, the team assigned 48 participants to one of two routines — three 90-minute floats, or three 90-minute rests in a reclining chair — and scanned everyone’s brain with functional MRI at the study’s start and finish. Floating, and floating alone, damped down the default mode network, a cluster of regions repeatedly tied to rumination. To Dupont this is a thrilling result, hinting that the tanks may ‘reset’ a nervous system that has drifted out of balance.
G
GThere is encouraging news, too: a number of cities have set about lowering the volume. Among the earliest was London. Diego Castellano credits a mix of measures — advice on running quieter buses, curbs on traffic noise and tighter limits on aircraft — with making the capital a markedly more peaceful place to live. Elsewhere, authorities have laid noise-absorbing road surfaces and planted belts of greenery to soak up sound; others have gone after particular culprits, from Washington DC’s recent outlawing of petrol leaf blowers to a New York rule that penalises drivers who tinker with their cars to make them louder. ‘Residents can feel the difference these calmer surroundings make,’ Castellano says, ‘and I would expect a good deal more of it in the years ahead.’
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Question 1 - 4
Which paragraph contains the following information?
A
B
C
D
E
F
G
1.
examples of actions designed to lower what the public hears
2.
figures showing how common damaging sound exposure is
3.
the immediate physical effects of hearing something unexpectedly loud
4.
a finding that some background sound can be better than none at all