it could be your tires on the pavement.
it does that because it has a generator which makes the engine makes these sounds
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.
humming noise is a bad ground to the radio. you may have a loose connection. connect a ground wire to frame of truck.
Wheel bearing.
Bad wheel bearing
A hummingbird
There can be a slight humming noise while driving a neon. This sound could come purely from the engine to indicate that it is running.
A humming noise in a 2001 Saturn SL2 when driving over 50 mph could indicate several potential issues. It might be related to worn wheel bearings, which can produce a humming sound as they fail. Another possibility is tire problems, such as uneven wear or unbalanced tires, which can create noise at higher speeds. Lastly, the noise could also stem from issues with the drivetrain or transmission components.
because something is about to break.
Could be a bearing going bad.
id say type and size of tire, and if bearings are bad either or will make that humming sound.
you need a noise filter! go to your local stereo shop and tell em you need a noise filter.