Welcome!
Almost always the pump. Shouldn't be whiny either - maybe it was telling you ahead of time it wanted the fluid changed.
How many miles do you have? Can you also fill out the vehicle profile so we know what driveline you have?
I'd start with sucking the reservoir out with a sacrificial turkey baster, refilling it with fresh fluid, then turning the wheel lock to lock 3-4 times, then doing the same thing again. 3-4 times and you should have almost all good new fluid in there. If it doesn't quiet down after that, confirm by listeneing up close while somebody else turns the wheel. Then look for pumps at your favorite parts vendor.