The final part of the Rolling Stone Article "The Death Of High Fidelity"
Loudness War
Since the mid-1990s, engineers have used dynamic compression to make CDs louder and louder. These waveforms show how loud contemporary recordings have become:
Nirvana
"Smells Like Teen Spirit"
Back in 1991, even the loudest rock wasn't always loud: "Smells Like Teen Spirit" has plenty of fluctuations in its volume — so when Kurt Cobain screams, you feel it.

Arctic Monkeys
"I Bet You Look Good on the Dancefloor"
This 2006 track is a prime offender: The sound wave is cranked to the limit, and it stays there for nearly every second of the song. Have a headache yet?

U2
"With or Without You" (Original)

U2
"With or Without You" (Remastered)

How does MP3 work?
MP3 reduces a CD audio file's size by as much as ninety percent, with an algorithm that eliminates sounds listeners are least likely to perceive — including extremes of high and low frequencies.
What is dynamic range compression?
This studio effect reduces the difference between the loud and soft parts of a piece of music — recently, mastering engineers have used it to make sure every moment on a CD is as loud as possible