Yes, but why is a high bypass turbofan quieter? If I understood correctly, it's because most of the thrust comes from the large slow moving fan, so you don't need to blast nearly so much air through the turbine as a turbojet to get the same thrust.
The whole purpose of decoupling the fans is to give you an even higher bypass ratio - two or three large electric fans driven from one turbine can have a larger swept area than a single large geared turbofan, so can run slower for the same thrust, and hence be quieter.
The noise comes from high speed air alongside slow moving air. A high bypass fan moves more air at slower speed to get the same push. The slower speed means less noise.
The whole purpose of decoupling the fans is to give you an even higher bypass ratio - two or three large electric fans driven from one turbine can have a larger swept area than a single large geared turbofan, so can run slower for the same thrust, and hence be quieter.