Οn automatically adjusting effects with vocal intensity

Hearing about it for the first time.
Thanks to Xenofon www.261.gr for pointing out to me and to Akis Golfidis for the generous explanation of this trick.
Is this a trade secret?


Possible examples as quoted by Akis Golfodis are:
Celine Dion
Sade
Frozen - Madonna
etc


Here is how Akis Goldidis explains it:
http://www.musicheaven.gr/html/modules.php?name=Splatt_Forums&file=viewtopic&topic=30180&start=20


In summary vocal is sent to 2 channels.
One channel is heavily compressed and set at a bit below comfortable level.
The other channel is left uncompressed set at a much lower volume setting and effects added.
So when singer sings intimately the compressed channel is heard.
At chorus the uncompressed channel is heard as its level is allowed to go much higher.
The overall effect is voice at listener's face at verse and effects automatically added at chorus, no compression artifacts.