Oh it's loud.
I had it happen when going out to the practice area for some "under the hood" instruction and the instructor thought the engine was about to expire because the rhythm changed with prop speed.
I remembered a guy had called an emergency landing on the same plane about six months earlier and landed at Andrews air force base but the cause wasn't discovered and he flew it back without incident other than a lot of paperwork and unwanted attention. It was coming up for another annual so it was inspected and nothing found amiss.
I pushed open my door and pulled the belt in and that was it.
The next time I went out for a pleasure flight, I found brake rotors on the floor behind the seats when I got in and quietly handed them to my friend who worked there and he said "I had thrown them away". It turned out that the previous "renter" had seen the rotors, deemed them still usable for something and forgot to take them out at his destination.
N4599L, a full IFR cessna 152 was later flipped over at W10.
I liked that plane.