driveshaft noise?

hi,i have been given an escort 1.3 1993 and when taking my foot off the accelerator there is a loud "dry" sort of noise which then goes off again when putting the foot back down..any idea's what this could be? it started around a week ago.gearbox? hope not or scrapping time i think.wheel bearing..driveshaft ? any sort of help would be great! TIA