Use of Generators to run Air Conditioners when camping

I've noticed some of the larger coaches, the generator cannot be heard unless right next to the exhaust and listening for it.
Ours is a 7500 Onan. I would love to find a better muffler as we have to run it sometimes for med equipment.
The exhaust tube that you run up to the top of the coach sound good but I have not found a satisfactory way to mount it and remove it when we leave.
Not sure it would kill all the sound.