The building I was in has 4 floors. Usually, it only cavitates between the 3rd and 4th floors.
This time, I could hear it as soon as I stepped in on floor 1.
The floor started vibrating as soon as the car moved, and it got so loud that I couldn't hear myself think. I could actually feel the car struggling to get to the 4th floor, it would kind of hover, sink and then go up, sink and then go up, over and over again.
Have you ever been in an earthquake? It's like that, but times 6.
(But remember, it is totally safe.)