Final answer:
During the prehistoric Age, people used cave paintings as a form of communication, depicting various aspects of their lives and surroundings.
Step-by-step explanation:
The communication devices that people used with each other during the prehistoric Age include various methods, but based on what we know today, cave paintings are a significant form of communication from that era. Cave paintings were often used to convey information about animals available for hunting, danger in the area, or possibly spiritual beliefs. They depicted animals, human figures, and abstract signs. The paintings are a testament to the early humans' capacity to give meaning to their surroundings and communicate complex ideas without a written language. While smoke signals, drum beats, and hand signals were also methods of communication used in various cultures, they do not pertain specifically to prehistoric times or are not as well-documented as cave paintings from that period.