There is no end to how much dogs communicate with each other. Likewise their communication with us is as much, if not more. When they communicate with one another; their signals are noticed much more quickly. We on the other hand can take forever to "get" a message; even miss them completely. But if you take the time to learn how your dog communicates with you; the whole world of canine communication will open up.
Communications between dogs and humans is done through vocal sounds, words, body posture and signals. Signals are very easy for dogs to learn; this is because they are all about visual body language. Implementing hand or body signals when your dog is young will prepare them for their senior years. Almost all dogs loose their keen sense of hearing to some degree as they age. Some lose it early, others may keep their hearing long into their old years. When a dog starts to lose their hearing; signals are a wonderful option to be able to fall back on. I'm there with Luke right now.
I remember signaling to my old boy Clyde (the man in my life before Luke) like it was yesterday. When his hearing got so bad that I could no longer use sounds or words I resorted to hand signals. They quickly learn to adapt and look to you for signals, rather than listen. Just this morning Luke and Elsa were out with their Dad. I leaned over the balcony to say hi and Elsa wagged like crazy at the sight of Mom. Luke on the other hand had no idea I was even there. I whistled and he did hear that but could not locate it's origin. Then I clapped which he also heard but it was my waving arms that told him where I was.
Signaling can be difficult if you don't already use it at least partially. If you start teaching hand signals when your dog is young and has their hearing; the transition as they age is much easier. You can use whatever signal that you'd like, just keep it consistent. I use a lot of signaling when my guys are young so that move to more and more signals is easy. It is also much more pleasant than yelling; I hate yelling but often there is no option. Teach signals and you won't have to yell quite as much.