Im sitting here in complete silence on the internet no ambient noise whatsoever (in basement) and i hear like an almost light grinding noise right from where the hard drive is located. i have a 2011 13in i5 and has been nothing but wonderful since i got it but i think this may be the first time ive sat in compete silience with it.....my question is is it normal for a stock HDD to make such noise from time to time...(sitting here i thought it was the fan at first but then its defintely coming from where the hard drive is) so do the stock HDD's make a certain noise from time to time??? im about to go insane lol please help