Some drives do support quiet vs. performance modes.

hdparm will set this for you, however, from the hdparm manual page:

      -M     Get/set Automatic Acoustic Management (AAM) setting. Most modern
             harddisk drives have the ability to speed down  the  head  move-
             ments  to  reduce  their  noise output.  The possible values are
             between 0 and 254. 128 is the most quiet (and therefore slowest)
             setting and 254 the fastest (and loudest). Some drives have only
             two levels (quiet / fast), while others may have different  lev-
             els  between  128 and 254.  THIS FEATURE IS EXPERIMENTAL AND NOT
             WELL TESTED. USE AT YOUR OWN RISK.

Good luck!

Gordon

Did it ever work for you ?
I may be unlucky, but I never seen this work for any of my drives.
Or maybe my ears are always polluted, and I hear the heads move even
in my dreams :-p....