https://www.enjoythemusic.com/magazine/viewpoint/0223/Limitless_Musical_Pleasures.htm

One obvious way to do that is to increase the total power of the radio station’s transmitter, but that’s subject to FCC (Federal Communications Commission) rules. Another way is to increase the average power output of the transmitter so that it’s operating as close as possible to its maximum output level at all times. To do that, more signal processing was added, and not only were music’s loudest sounds compressed toward the average level but its quietest sounds were expanded so that the volume level transmitted could always be as near to the limit as possible, maximum broadcast coverage could be maintained, and the largest potential audience would be assured.

That satisfied nearly everybody – except for music lovers and audiophiles. A very important part of the vividness and realism of a recording lies in its dynamics. The crash of a cymbal and the “kick” of a kickdrum are thrilling parts of the musical experience and are major reasons why so many people love horn loudspeakers.

Now, though, combining digital recording, the computer, and the internet, more than 60,000 radio stations can present your favorite music on-line, around the world, so the old reasons for signal compression or expansion simply no longer apply, and artists, engineers, and producers can concentrate on their art and on making recordings that don’t have to compromise their dynamics in order to ensure the largest possible audience. Hopefully, a new kind of radio will result in new, un-limited, higher fidelity, more dynamic recordings, and even more opportunity for us to..