Honda CRV Door Noise

I have a 2000 CR-V.
The drivers window won’t go down and has been like that for about 18 months.
But just two months ago, when I go to lock the door either with the key or from the inside with the lock all doors switch, it makes a noise for about three to four seconds. Like - UMMMMMMM.
Door still locks OK.
What causes the noise?
Thanks all