It's a subtle difference, but the click of death tends to be louder than (what I suspect) the OP is hearing.
If it sounds like a muffled tap and it occurs after a period when the drive's not being used, chances are it's just the read/write heads parking themselves. You can change the sleep interval using hdparm, but it's really not necessary. The load cycle count of most laptop drives is far, far higher than server drives, so unless you have reason to suspect that your drive is sensitive to load cycles I'd just forget about it.
Still, backing up regularly is always a good idea...