We can copy the engineering moves of the
Pioneer DVR-A16J-SV (not currently available in the west) and reduce the noise by about half with just some very simple modifications.
1st, use a double layer of electrical tape to cover all holes and case seams.
2nd, add o-ring sealing to the inside of the front bezel. In place of this if you don't have or can't find an o-ring that large, again use multiple layers of electrical tape so that when the drawer closes it creates a dust and noise seal.
This is all Pioneer did and the drive is VERY VERY quiet! Well they also engineered a more stable spindle which probably helps too.
If you use tape on the front inside the bezel, you might have to split the tape lengths down the middle (so they fit on both sides [above and below the trey shelf]) and make sure not to overlap the ends.