1999 Mercury front and humming noises can because by several things. Tire noises are the most common cause. A tire that is not wearing properly can cause a humming noise.
Humming noise on the front passenger side of a 1997 Ford Explorer XLT may be due to a bad tire. Try to jack up the tire and spin it by hand to see if the noise is there.
Most commonly this is a tire wear issue
A hummingbird
Yes.
Could be a bearing going bad.
it could be your tires on the pavement.
you need a noise filter! go to your local stereo shop and tell em you need a noise filter.
Bad wheel bearing or there is a problem with the tire itself.
sounds like tire/road noise
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.
Check the bearings.