To avoid unneccessary hard disk noise you may use the same techniques as described in the power saving chapter. Hard disks in most laptops are the primary source of noise. Modern laptop and notebook hard drives come with a so-called "Acoustic Management", just have a look into the manual to get an overview about the possible settings.
The noise of the hard disk can be very disturbing, see man hdparm to reduce the spin of the disk.
Some hard disk manufacturers offer dedicated tools, e.g. Hitachi's Feature Tool allows to change the drive Automatic Acoustic Management settings to the Lowest acoustic emanation setting (Quiet Seek Mode), or Maximum performance level (Normal Seek Mode).