Although pools are not my main line of work, I can offer some questions and maybe they will trigger you to think of a solution to the noise problem. First, if the noise seesm to be fairly loud and sound like metal rubbing on metal, it may be telling you that a bearing in the motor is about to go bad. If so, then you need to take the pump to a service center and see if they can replace the bad bearing, The same type of sound can result from the shaft of the pump motor being out of alignment with the pump casing. If so, you may need to take the pump motor and housing to a service center where they can check the whole thing and make sure the parts are properly aligned. It may also be a sign of the impeller going bad, although most of the water pumps have a fairly long lifetime when it comes to the impeller. After all, it is only pumping water ... we hope!
Unless you or someone you know is a qualified motor and pump person, this is something that you need to have done by someone who has the proper tools and knows what the pump and motor are supposed to sound like.
If you take the pump and motor to a service place, try to record the sound of the working pump, using a tape recorder, and bring that with you ... because it may give the technician a clue about what is wrong and what need to be replaced.
I applaud your decision to try and keep it running. Replacement pumps and motors are very expensive in the pool equipment supply houses.
Now, if the pump noise turns out to be in the normal range for a pump of that age, you may want to consider putting some kind of barrier between the pool and the pump equipment. A barrier might just be a wall, to screen out some of the noise. Some plants might also serve as a barrier to cut down on some of the noise, if placed across the path between the pool and the location of the pump.
Don't cover the pump entirely! That might lead to overheating and could result in failure of the motor. Good luck. Sonds like you have a real problem. When you decide to replace the pump, get one of the QT (quiet) pumps. They really drop the sound level noticeably.