Warning signs for low brakes

I have a 97 Cadillac Deville. I've been hearing a buzzing sound from the rear by the tires. Does anybody know if that's a warning signal for low brakes?

I have a 97 Cadillac Deville. I've been hearing a buzzing sound from the rear by the tires. Does anybody know if that's a warning signal for low brakes?
That buzzing soun may be your electric fuel pump. Often they make a soft buzzing noise when the engine is running. If its loud or harsh, the pump may be failing.
For worn brake pads, often disc brakes will make a squealing sound whenever its in motion, becoming louder when you step on the brakes, but never a 'buzzing' sound.

Thx. I will check that out.