If your ears were infinitely sensitive, you could hear it. 128kbps retains almost all of the sound quality.

It actually is quite close unless there's a lot a of details in the original song. Like if it were a big band, the 128kbps MP3 will most probably miss out on some of the softer instruments. But still the difference is quite little.

There are a number of reasons, some of which people really don't like to hear. Since I find the difference painfully obvious on a lot of music, here's a list of possibilities: 1. You don't know how to listen to music or what to listen for. Very few people actually sit down and seriously listen to music. Most have something playing in the background when they are doing something else. Listening takes concentration and practice, just with any other skill. It's worth the effort. 2. Your equipment is inferior. The quality of much home audio equipment has deteriorated over the past decade. This is partly due to the 'Wal-Mart' effect, as I call it: products reduced to the lowest cost commodities. A $100 audio system does not sound remotely as good as a $500 system did ten years ago. To lower the price to that extent, a lot is taken out. (That said, a modern $500 amplifier probably sounds better than its $500 counterpart did ten years ago.) Boomboxes, computer audio, and 'Wal-Mart' systems are low-fi. And much equipment is merely mid-fi. Most people don't know what a really good source sounds like. I didn't until about five years ago. 3. The quality of the original recording is poor. Surprisingly enough, with the vast array of quality recording and editing hardware and reams of technical experience to draw on, many recordings (particularly of the pop persuation) are lousy. They are compressed, equalized, re-equalized, and reverbed to death to make up for flat multi-miking in an acoustically dead environment (and then buried in the backyard for months until they fester just the right amount). Or they are produced to sound sharp and flash on low-fi hardware, such as boomboxes and computers. Equipment of this quality is known, colloquially, as "shitboxes" in the recording industry. Too much pop music is engineered to "shitbox" standards. There's no reason for this except disrespect for consumers and a desire to chop costs. There is no excuse for poor or even indifferent audio quality on recordings. ------------------------------------------------------------ Re: "Para 3 is a little unfair" My position is that consumers purchase audio recordings with an expectation of quality, which is often absent. The recording industry today has access to very good equipment at a modest price, compared to even 20 years ago. The cost of producing a quality recording is not much more than producing a poor one. Rather than pandering to the lowest common denominator, I think it better they service as many consumers as possible. A "good enough for kids" attitude doesn't do this. Recording companies have been doing this for decades, beginning with the low-quality vinyl used for some mass-market LPs and most 45s in the 1950s. A portable player does not mean low-quality audio. While there are numerous $100 portable audio players on the market today, the most popular by far is the Apple iPod. It is considered the best in terms of audio quality and, unlike any other, will handle higher-quality lossless audio formats. The iPod has spawned an industry of audio upgrades. The Apple headphones can be replaced with better ones, such as the Shure E-series earphones, and external amplifiers and speakers allow it to be used as the basis of a decent music system for the office. Apart from the iPod, just about any player can be improved by replacing the stock headphones.