The telescreen received and transmitted simultaneously. Any sound that Winston made, above the level of a very low whisper, would be picked up by it, moreover, so long as he remained within the field of vision which the metal plaque commanded, he could be seen as well as heard. There was of course no way of knowing whether you were being watched at any given moment.
How often, or on what system, the Thought Police plugged in on any individual wire was guesswork. It was even conceivable that they watched everybody all the time. But at any rate they could plug in your wire whenever they wanted to.
You had to live - did live, from habit that became instinct - in the assumption that every sound you made was overheard, and, except in darkness, every movement scrutinized.
When I was young I read George Orwell's 1984 almost out of a sense of duty. It was the supreme expression of what we, as a society, were against. It made you realise how lucky you were to live in a free society.
One of the consequences of the collapse of the Soviet Union is that we no longer have such a strong sense of what we are not like. The other day the Daily Mail had a front-page story about data from traffic cameras being used for other purposes by the police. The headline YOU CAN'T ESCAPE BIG BROTHER just did not work. Anyone reading it would assume that someone had tried to get out of Channel Four's house and been brought back.
Similarly, it is not so long since a story like this one from the Herald would have made every educated reader think of Orwell's telescreen:
A controversial plan for CCTV to be used to protect children in the homes of chaotic drug-abusing parents has been proposed by one of Scotland's most eminent drugs experts.
Professor Neil McKeganey, head of the centre for Drug Misuse Research at Glasgow University, believes radical measures are required to protect the estimated 160,000 children in Scotland living with an alcoholic or drug-addicted parent.
Today, I doubt that there will be any such reaction. And it is a slippery slope. If drug addicts, why not child abusers? If child abusers, why not those with a record of other violence? And if so many people are already covered, why not extend it to everyone? If it saves one child's life...
So if we don't read Orwell any more, where are the cultural resources that will give today's young readers an instinctive feeling for what tyranny is like and why we should oppose it?
Thanks to technovelgy.com for the quotation from Orwell. It also has some interesting material on earlier uses of "telescreen".