Most of the simple tech drives I've worked on had Seagate or maxtor drives inside, not to say they all do, but generally tones are indicative of physical problems, after a drop, usually spindle issues, if the drive was spinning when it hit, it is probably a bent,seized spindle. This would require pro recovery in a clean room - probably starting about $1200 and up USD. Unfortunately this is not something you can do at home. Check out the sounds here, and see if any are like yours. Don't limit it just to Seagate and Maxtor because you can't be sure till you open the case what is inside.
http://datacent.com/hard_drive_sounds.php