If you cover the pump, it won't get the necessary 'air' to keep cool. Covering it will trap the air and shorten the life.
I don't know how big your pump is but the 'perfect situation' is to have the pump / pump-house a good distance AWAY from the pool to keep it quiet around the pool. Would you consider having it moved? Perhaps it can be 'buried' or recessed into the ground a bit. YOu'll have to talk to a pro.