Anyone have any experience with general laptop hard drive noises?

Inside your harddrive case are three to six disks with magnetically recorded information. These disks have a arm on the top side, and on the bottom, that goes back n' forth HUNDREDS of times a second. Bound to be a little noise. Western Digital harddrives, I have found to be more quiet than other makes. Go to Howstuffworks.com>Computers>Harddrives. They show an illustration or two. I opened an old one once to check it out, REALLY clean inside!(Once they're opened they're crap! They are made in a dust free clinic type environment!)