I would suggest that the first thing to do is by hearing protectors.

Haha, well we have the
replacement fans ready to install. And these will be in a server room kept nice and chilly.
which replacement fans did you choose to use? I would appreciate a link if you have it. Thanks.
I bought the Delta AFB1212SHE units in bulk. Also have the Noctura Fans but will test and send back if the Deltas cut it.
Strato