you need a noise filter! go to your local stereo shop and tell em you need a noise filter.
the humming noise is coming from a bad ground on you stereo
where is the humming noise coming from? if it's coming thru the speakers and matches the rev tone of the engine, then you have a bad ground in your stereo.
A hummingbird
it could be your tires on the pavement.
id say type and size of tire, and if bearings are bad either or will make that humming sound.
I have heard that if you have papers or napkins in the glove compartment box they can get sucked into the air vent which then makes a humming noise that you can hear while driving and as you increase the speed the pitch of the noise gets louder.
its probably your radiator
Certain types of tires may cause a brief humming noise after your initial acceleration. The transmission may also cause a brief humming noise.
it does that because it has a generator which makes the engine makes these sounds
could be your wheel bearings
Not much info to go on but, it could be a wheel bearing going bad.
MAKE CAR MAKES THE SAME NOISE AND REPLACING THE PVC VALVE FIXED THE PROBLEM