Our old neighbors downstairs were very quiet. They moved at the end of the summer, and the new tenants in their place are not so quiet. One of them has a motorcycle, and he frequently works on it in the parking bay immediately under our apartment. When he works the smell of exhaust wafts through the windows, and the rumble of the engine shakes the floor. The way the floor resonates is interesting for the first few minutes; then it gets old.