I've owned several FWD cars and the clicking, especially while turning or accelerating, is a pretty sure sign of a CV (constant velocity) joint going. So if your mechanic told you "joints," +1 to that.
You can usually drive a ways (5000mi/8000km) before the sound becomes unbearable. I never got past the clicking phase, but I'm told you eventually start hearing knocking, then screeching metal, and finally it just busts, possibly taking other components with it. So, probably should fix it before that.
In case you wanted to try something DIY, I've heard some guys pull back the CV boot (the rubber sleeve) and repack grease to delay the job. Might be doable on your Volvo.