It's really hard to understand what you're asking here.
"What causes a knocking sound when your car drops into a hole while driving?"
If that's your question, I imagine that it would be the sound of your car dropping into a hole.
tie rods
Blowen motor
you could have a wire broke in the tire
check CV joints
You have slowed down.
mobile phones
The correct answer is : drinking and driving
The knocking noise could be one of several things. The wheel bearing, a worn steering or suspension part, or road debris could be causing the noise.
check CV joints, if bad replace shafts and joints assembly
I experienced a knocking noise in my 03 Xterra and found out is was a bad wheel bearing seal and had to have the Nissan dealership replace it for about $400 (includes labor and parts).
The knocking that you are describing reminds me of a stuck universal joint. A bent axle usually wears tires out very fast more than making noise.
Drinking while driving