[ageitgey]

Of course the medium changes the context. It has a huge effect!

Phone calls are typically person-to-person communication where you can hear the tone of voice of the person you are talking to, so you can better read their meaning. Also, you typically call people you already know well enough to disturb. It's a very personal form of communication.

Facebook is different in all those areas. You are thrown into meaningless conversations with people you don't know where you can't hear anyone's one of voice. Some parts of facebook seem to be designed specifically to encourage more conversation instead of meaningful conversation - things like how you really have to dig to read earlier comments in a thread. They just want you to keep posting instead of following the actual discussion in a coherent way.

Likewise, posting on this site is different than having a conversation in person. You can't tell that I'm writing all this in a friendly tone. Instead, it might come across as an angry argument when I don't mean it that way. That's a disadvantage of this medium and a way in which it changes communication.

[ProAm]

You can send voice messages over facebook. [1]

[1] https://www.facebook.com/help/377884675632666