Another Voice | 28 February 2009

Some time ago I was in a room containing perhaps half a dozen other adults, a cat on a sofa-arm, and a baby in a carry-cot far from where I was sitting. The air was filled with the noise of general conversation. I had a cold. I coughed.

The baby almost jumped out of its cot. The cat jumped. Nobody else moved. None of the adults (even those near me) flickered an eyelid. None so much as registered having heard the noise.

Last weekend I returned to our house in Derbyshire, where my brother and his wife, their two children and their beagle dog were staying for a few days’ break. That evening we sat around the kitchen table eating the delicious meal my sister-in-law had cooked. The dog was under the table. My sister-in-law was in the middle of a gentle anecdote about something or other; we were listening quietly; and she was speaking quietly. All at once, without interrupting her flow, she bawled ‘Get down!’

I jumped. Her husband and children showed absolutely no sign of even having heard her, let alone of surprise at the sudden shout. The dog, which had been eyeing some untended food on the table, did get down. My sister-in-law reverted to her quiet voice and carried on with her tale.

In these two stories the closest we have to what in the environmental health world are called SLMs — sound-level meters — were the baby, the cat and (in the kitchen-table case) me: Uncle Matthew, unfamiliarised with the cultural codes of a family with a young dog-in-training. Our reactions were raw, objective responses to a given level of decibels. A sharp cough is a very, very loud noise, much louder than ordinary conversations. We — cat, baby and I — are to be contrasted with all the other people who, unlike us, had been acculturated to what were really examples of private language within a language. In this private language the words ‘get down’, when addressed to a dog as a reproof, can be delivered at an ear-splitting level without arousing any surprise; indeed, ‘ear-splitting’ is the only level on which the reproof works, as it indicates to the dog that this part of what the humans are saying is directed exclusively to him.

Likewise, the ordinary language of adult humans can include coughs and clearings-of-the-throat without their being properly factored into what is heard: we screen them out as rogue or junk sounds, white noise, signifying nothing, just as the clever Hansard reporters of the House of Commons remove stammers and repetitions from the spoken words of MPs and render them as ‘clean’ text in the Official Report.

Where private language and public language overlap, incomprehension, misunderstanding or shock can occur. Which of us has not been quietly scanning the shelves of a supermarket only to be interrupted by the most incredible shriek, often right up close to us, of a mother yelling at her errant toddler? Everyone else spins around in the aisles, momentarily fearful that a terrible accident has occurred, only to see the mother resume her shopping, apparently unruffled, while the toddler looks up mildly, then continues his explorations, taking it all in his tiny stride, thinking, no doubt: that’s how mothers do talk to you when they’re a bit bothered, isn’t it?

I noted the same phenomenon in my carriage on the train to Derby last week, where — to the (at first) alarm and consternation of the rest of the carriage, two elderly Chinese women passengers were chatting merrily away to each other at the top of their voices. At first it sounded is if they were having a blazing row, but no: that is how Chinese people often do seem to speak among themselves — perhaps on account of its being very crowded in China.

On one level this is unsurprising. Different groups, different races, different social situations, evince different ways of talking and of hearing; and we need to learn to take account of (and therefore discount) the differences. But that’s at the intellectual level: the level that says, ‘Yes I did hear that cough but I know it to have had no bearing on the conversation, and so decided to ignore it.’ This, as I’ve noted, is acculturation: the way humans learn to interpret the raw data delivered to them by their senses.

But on another level, something rather startling is happening. Because, you see, the other people in the room didn’t hear and discount the cough, and the baby and the cat didn’t hear and take fright at the cough: no, the other people didn’t hear the cough at all; and the baby and the cat did. If you’d asked the other people, later that day, whether they’d heard anyone cough they would quite possibly have said no.

The screening out takes place at a deeper level in our perception than in just the conscious, acculturated mind. Scientists report that the parent penguin, swimming in from the ocean to be confronted by tens of thousands of penguins and their chicks, all shrieking (and if you’ve ever heard the cacophony you’ll know what I mean) — can hear through all that noise the particular squeak of her own chick, and make for it. They call this the ‘cocktail party effect’. You haven’t, at a noisy reception, ‘heard’ what those whose conversations do not concern you were saying. You only heard a vague hubbub. Through it, what you did hear was the one conversation in which you are involved.

Curious. But important too, for this reason. Screening in and screening out — focusing with all our senses, not just our eyesight, on what we think we need to register — does not take place at only the conscious level, but at a level closer to what we suppose to be our raw, immediate, unrationalised perception of the word: our sensory perception. We take sensory perception very seriously indeed — ‘I have to believe the evidence of my own eyes/ears,’ ‘the camera cannot lie,’ etc — supposing this to be primary data, objectively recorded, and according it a more solid evidential basis than the interpretations we may afterwards make of the raw evidence. What we don’t realise is that this ‘raw’ data is itself an interpretation of the world. Unconscious preconceptions have already screened out what they have deemed irrelevant.

Cultural and intellectual judgments on the shape and meaning of the world interpose themselves on what we see and hear, before we even see and hear it. Not surprisingly, the evidence then tends to confirm the wisdom of those judgments. The baby, the cat and Uncle Matthew may report a loud and unpleasant noise, but nobody else heard anything untoward.