Do you have a Duratec V6? If you do it's called "moosing". It can be fixed by replacing the idle air control valve. It's nothing serious, just loud and embarrassing.
If it sounds like its coming from inside the car its probably the fuel pump if not its kind of hard to say.
Check your fuel pump
sounds like a vacuum leak some where in the system
that could be a wheel bearing that's gone bad.
They got their names as humming birds because when they move their wing very quickly And from that humming sounds come this is why they are called humming birds
From the sound its wings make from flapping so fast. It sounds like they are humming.
I wonder if your a/c compressor is going on the blink? If you can disconnect it somehow, does the humming stop?
Since Blu-Rays take a while to load the disc, there will be sounds such as humming and even sometimes some clicking, but these are perfectly normal
A humming bird
The speed of sound depends on what the sound is going through, not on what created the sound. If sounds from different sources had different speeds, then there could never be a band, orchestra, or choir.
sounds like tire/road noise
You know its a hummingbird because of the humming of their wings. Otherwise they make a chirping sound, like a normal bird.