Well, sedan, hatch, and coupe. I'd venture to say that the coupe and sedan are closely related, and the hatch is a close cousin but they aren't precisely the same cars.
Speaking of sound insulation: does anyone else have an opinion of the carpet mats that are attached to the underside of these cars? It's the same weird felty material that the inner wheelhouses are made from, and not entirely dissimilar to the thin and lousy product that is installed as "carpet" in our Civics. I was a little surprised when I saw them there and - living deep within the rust belt - I wonder whether they'll trap the salt and brine that are heavily coating the roads here half of the year and encourage the floors to rust.
Regarding actual sound: hatchbacks are typically a bit noisier than your sedan and coupe due to the trunk area being open to the passenger cabin. It functions as an echo chamber, plus the part of the car with the rear wheels is effectively inside of the car now instead of being separated by a bulkhead. The radio doesn't sound as good in a hatch either, but a price must be paid to have the utility of that large opening at the back.