Alu Macbook Excessive "Thinking" Noise?

Hello, I have the 13'' Macbook, this is the second one I've had in the past half month. The first one had a constant whine coming from the hardrive, so they gave me a new one, within days this one started doing it too, but I've just learned to live with it, my room is really really quiet so whatever.

Anyways, lately my new one makes a parking head noise usually when I'm not doing anything, if I just leave the keyboard and trackpad alone, it does it maybe one or twice, but I've read that's normal, I think.

However, lately it's starting to make that noise that all computers make when it 'thinks', that little light noise that I can't describe, but you probably know what I'm talking about. It didn't do it before and I can't seem to click a link online without hearing it, it's not too loud, but I just want to make sure that's normal considering it only just started becoming audible.

Does anyone else's do this? Can you hear yours 'think'?

 

Well, it only does it when I'm accessing pages, when the pages are done loading it pretty much stops until I load a different one, which I can imagine is normal.

but it didn't use to do that, I've been paranoid about my Mac having issues since I got it.

If you click a link or go to a site, should you be able to slightly hear the hardrive make that noise?

 

Because I see so many people saying their late 2008 macbooks are dead silent even during activity.

 

Thank you very much! :]