you'll more likely "feel it" rather than hear it.
depending on the engine house, you may not hear more than a low rumble, certainly quieter than a diesel.
Imagine is right, the water splash is louder than the exhaust. Inside the cabin? Should be able to speak in normal voices, no hand signals needed.
If its troubling, you can get sound deadner from almost any autobody supply house, and 3M has a good spray on glue.