Why does the car get a "rumbling" noise in the front? on 2004 Volvo S80

On a smooth road at speeds over 30 or so, a rumbling noise is hear from the front end. (no vibrations or shaking, etc. -- just the noise.) It seems to increase in volume as the speed increases? Thanks.

by in Isabela, PR on March 21, 2012
2 answers 2 comments
ANSWER by on March 21, 2012
POSSSIBLE FRT HUB BEARING GOING BAD OR BAD TIRE
COMMENT by on March 22, 2012
Thank you. What is a hub bearing and would a local mechanic be qualified to replace it or would I need to go to Volvo?
ANSWER by on March 22, 2012
I agree. Most likely hub bearing.
COMMENT by on March 22, 2012
Thank you. What is a hub bearing and would a local mechanic be able to replace it or would I need to go to Volvo?