I have a Trane XE 90 gas forced air furance which is about 10 years old. When the blower kicks on there is a humming noise which then goes away after a few seconds. It is rather a loud noise. What can be done to prevent this noise?

I have a Trane XE 90 gas forced air furance which is about 10 years old. When the blower kicks on there is a humming noise which then goes away after a few seconds. It is rather a loud noise. What can be done to prevent this noise ??
I just posted a message about the blower won't turn on.Your posting reminds me that I did notice the same noise with my gas York furnace as well s couple of weeks before the blower stopped to work. I do not know much about furnace, just wondering if it's some kind of indication and you should not ignore it (otherwise may end up with a situation like mine)