Shouting is a common occurrence today. This is caused by people having their Caps lock key left in the on position. With all those unreported alien abductions, 80% of all humans now have a full keyboard installed without their knowledge. So today, people can be heard shouting anywhere, at any time. And it is plenty irritating when the great bass sounds from your car stereo system are being drowned out by someone shouting on their phone.
So, be a nice guy and help shouters unstick their Caps lock keys. Put on your human skin mask (sanitation first!) and fire up your trusty chainsaw. Then run toward them to get their attention so you can offer to fix the key with your chainsaw. Their shouting might turn into screaming for a moment at that point, but you will note that in most cases, the area has suddenly got quieter. Their running or waddling probably caused their Caps lock key to unstick by itself. If so, you can do a permanent fix or can go back to hanging from a tree like a bat, or whatever else you were doing.
And don't blame the band Tears for Fears for their 80s song for making people shout. Nobody heard it then and if they did, nobody remembers it now.