How to add pool pump sound proofing?

[cade]

There is a low machine noise hum from my neighbours pool pumps close to our bedroom windows that operate at night though to the early hours in the morning 

A thin rubber mating has been placed under the pumps with out any other enclosure around the pumps 

loads of area around the pumps available  for placing acoustic panels and a house Looking down on pumpsHouse wall with switch boxeswall to support any acoustic panels 

pumps are mounted on a concrete slab 

Any advise or experience anyone has on setting up sound proofing around the pumps would be a big help before I head off on a trial be error effort