When you download and listen to an MP3, what are you listening to? A good approximation of a musical performance?

No.

How about with more efficient Dolby audio files, Microsoft Media, Real Networks, even newbies like Ogg Vorbis?

Nope.

The fact is, there's not an audio file out there that comes close to what the ear hears, and that's because they're all designed to fool the ear.

And the eye. Video Net transmissions do the same. They fool the eye just as the others fool the ear. The question is: do you really want to be fooled?

The answer is maybe, in certain circumstances, but only when you're really aware of what's going on.

The worst of it is that the issues of fidelity of reproduction of audio or video are intimately linked to your ability to hear or see in the first place, and that is a land of illusions. Those illusions are the basis of human perception and the bedrock of how streaming media will deliver audio and video in the future. Let's look at some illusions.

How About a Gorilla?
Anybody can see a gorilla. Put a gorilla before your eyes into any context and it's going to stick out, right? Don't count on it. Context is everything.

Last year, Harvard researcher Christopher Chabris showed people a videotape of a basketball game and asked them to count the passes made by one or other team. After about 45 seconds, a man dressed in a gorilla suit walked slowly across the scene, passing between the players. Although he was visible for five seconds, 40 per cent of the viewers failed to notice him. When the tape was played again, and they were asked simply to watch it, they saw him easily. Not surprisingly, some found it hard to believe it was the same tape. On the live viewing, watchers were too involved with all the other action to notice the gorilla. For more on that bizarre event, check out the New Scientist article on it.