How has the computer changed the way people communicate with each other?

They have most certainly changed the way people communicate. People can engage in live chat, email each other, and post on social network sites. While email doesn't send vocal cues like with phone calls, you gain the advantage of being able to attach files, including audio, video, and photographs.

In some cases, they have also increased the amount of communication, though the quality of communication is debatable. Rather than call someone long distance or write a letter a few times a year, some folks may email each other several times a week instead.