I only have one macaw and she is not as bad a screamer as the ekkie but, altogether, my birds produce a fair amount of 'noise' and with all the windows in the birdroom always open during the warm weather, you can hear them from outside and we have lots and lots of wild birds all around us.

It doesn't have to be a hawk, especifically, a feral cat or even a house cat that likes to hunt and is allowed outside could have made the difference in the neighbor feeders. Sounds like your neighbor doesn't like your birds outside to me.