2006-04-02 - 12:38 p.m.
During audio production when there is a concern that the audio levels are too low to be heard clearly there is a process that is performed known as compression.
Compression basically entails raising the low points in an audio signal to bring them closer to the peaks. Overall volume remains the same, but quiet sounds are amplified to bring them more in line with the louder sounds. Commercials frequently use high compression which is why they sound so much louder compared to the programme you're watching despite the volume knob being in the same position.
The principle problem with compression is that it reduces the dynamic range of the recording. Where once there was a wide range of sounds and subtlety between the lows and the highs there is now a much more uniform signal. That's why say a Beatles recording sounds so much more nuianced than an album by The Prodigy. The volume is actually the same, but compression squishes everything together into one cacophonic mess. Good for drum 'n bass, not so good for melodic pop.
Sometimes that increased intensity is desirable, the lower and mid tones not being so important as the THUMP THUMP. It would be a mistake however to take this as an accurate reproduction of the original music.
