Disks can make noises too; the noises can becomes 'sharper' and produce more vibrations. This would indicate a problem with the fluid bearings, though it does not have to indicate imminent failure. Such disks can survive for many years.
So while you can't really be sure whether its the fan or HDD without testing this yourself (stopping the fan with a toothpicker or whatever), you could just ease your mind by buying an external 2,5" backup disk and copy your stuff there, so you won't have to worry about losing your data.
Backups are the most powerful instrument to protect your data, with the current low HDD prices, a single external disk should be enough to backup most people's valuable data. Consider this if you feel uneasy about a possibly failing disk, since this really could happen at any time without prior warning.
The SMART data you posted earlier (can't access it now) didn't seem to have any signs of failure, though.