On my PC with 5.1 Surround Sound I have to turn the master / windows volume up to 90% to even hear it.
Switched over to my external sound card with a headphone amp and still have to crank up the volume. Have to blast it through my 12" PA speakers to get a good feel for the sound.
This seems to be the issue with all the codemasters games in my collection.
I play ACC and if I want the people in the other room to hear it I turn the master volume to 40% and it's loud AF.