Why MP3?

By: Brent Lundell
Submitted: 2008-05-16 13:00:29
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MP3?

Seriously. MP3 Players, MP3 Files, MP3 CDs. MP3 downloads.

But why?

Right Time, Right Place?

The basic answer is simple. Right place, right time. MP3s came out in 1991, just in time for the computer age. It's nice to be first, especially when you're making bank. The MP3 codec is owned and every program that saves them has to pay Thomson Consumer Electronics a little something. I bet they love iTunes.

And in the early computer age, when hard drive space was all important, the smaller files made a huge difference. Data loss wasn't important as long as the average user could fit a dozen CDs on their machine.

Data loss?

Yep. MP3s are a lossy format (as opposed to lossless), meaning they dump data. It's what data such things dump that matters though. MP3s drop some of the sounds, reducing the quality of what you hear. But why do we stand for it? Well, because we can't hear it.

Psychoacustics is the study of brain/ear interaction. Simply put, there are real sounds, floating in the air around us, and fake sounds, which our ears put together. For example, there might be harmonics (additional frequencies of sound related to the original sound) that our ear drum creates. They're not "real" but they are heard.

Temporal Masking

But there are also "real" sounds we can't hear. Temporal masking is a fun one. If there's a loud sound, it'll mask a quiet sound. The louder the sound, the more time can be between them. The freaky part? The loud sound can mask a quiet sound even if it happens AFTER the quiet sound. So someone could say "die", shoot you (in that order) and you'd never hear the guy's voice.

The brain just figures the louder sound is more important. Or something.

Frequency Masking

What does MP3 use? Mostly Frequency masking. Some frequencies hide others from the ear. Generally a lower note (say, a base drum) might hide a note a little above it. Such higher notes would need to be louder in order for the ear to pick it up. (That'll come as a surprise to a lot of audio engineers by the way. Try some new EQ tricks with that in mind.)

So an MP3 encoder will look at a the frequencies near each other and say, "hmmm, no one will hear that" and toss the extra. You think you're hearing everything. And you are. Just not everything "real".

Quality

Let's face it, nothing's perfect (except me). Some people can hear the sounds lost and notice. Others can tell when the top end is chopped off. MP3 starts to dump very high frequency sounds, which some people can hear (especially women and teenagers).

But there are ways to increase quality. Every MP3 file has a "bit rate". The higher the rate, the better the sound. CD quality (before being reduced to MP3) is 128. Most people won't notice the difference between CD 128 and MP3 128 but some will. Amazon uses 256.

That's huge. About the best you're ever going to find.

But, the big reason for Amazon, rather than iTunes, is lack of DRM.

DRM

Digital Rights Management is used to keep files safe. It encrypts the file such that only certain programs can open it (say, iTunes). And only if you're authorized, usually via a database on their server, to use it. I'm not a fan.

It's a hassle and fights with you. Sometimes it won't let you put it on other MP3 players (non-iPods) or open it with a different program without logging in. No access to the Internet? Too bad. Welcome to something dragged over concrete. Cover your ears.

It's annoying and I'm not willing to deal.

Amazon doesn't use it, which is probably part of why they don't have every song iTunes does. But avoiding the aggravation is worth it. To me anyway.

Article source: Expert Articles