My personal thinking was that as there are more roads, cars, machines and industry since the 1940’s, records simply tried to continue to be audible when played so they HAD to increase volume. That is not the article’s explanation, however.

Also interesting how this war ended:

> Mastering engineer Bob Katz had argued that "The last battle of the loudness war has been won", claiming that mandatory use of Sound Check by Apple would lead to producers and mastering engineers to turn down the level of their songs to the standard level, or Apple will do it for them. He believed this would eventually result in producers and engineers making more dynamic masters to take account of this factor.