Loudness War
The phrase loudness war refers to the music industry’s tendency to record, produce and broadcast music at progressively increasing levels of loudness each year to create a sound that stands out from others and the previous year.
This phenomenon can be observed in many areas of the music industry, particularly broadcasting and albums released on CD and DVD. In the case of CDs, the war stems from artists and producers desires to create CDs that sound as loud as possible or louder than CDs from competing artists or recording labels.
However, as the maximum amplitude of a CD is at a fixed level, the overall loudness can only be increased by reducing the dynamic range. This is done by pushing the lower level program material higher while the loudest peak sounds are either destroyed or severely diminished. Certain extreme uses of compression can cause distorting or clipping the waveform of the recording.
Image: The trend of increasing loudness as shown by waveform images of the same song mastered on CD four times since 1983.