On reading and communication

What is the difference between writing and speaking?

It's there.
You know it. I know it, but what is it?
Or is it?

It's a topic I've spent a fair amount of time thinking of, and this is my take on the problem.

I'll assume you're familiar with the scene where a lovestruck person sits at a table, pen in hand, and writes a letter. Attempts to write one is a better description we find out when we learn about the discarded earlier attempts crumbled on the floor.
I'll get back to this scene later.

We like to differ between spoken and written communication, and I believe that those two words sometimes confuse us. Both refer to the sender, the one who speaks or writes.
In ways the recipient is far more interesting.

Let's have a look at spoken communication. It's so much more than the words. Tone, facial expressions and probably smells as well. A good reason to be more careful when you're in the phone as you only have tone to go by. Misunderstandings become a measurable risk.
We take the non-verbal aspect for granted. Or maybe I should say the non-word based aspect. The phrase: "Could you please repeat that again?" becomes a polite request to make certain you got the message right, whereas in a face to face conversation it could be taken as impolite.

Remember that I'm still talking about the receiving end.

Now, what about the written counterpart? Well, first of all we are aware that we're limited to the words alone. The words we see confer the entire message. They're deliberate, thought through, weighed and valued. In other words, they've passed a test.
We take that writer of letters for granted. The words we read are not, can not be, the ones written on small balls of paper lying on the floor.

Comes the era of immediate written messages. Email, to a degree, but mostly chat-rooms, IRC or whatever you prefer to call live written communication.
Here we err. We read the words. We know that what we read was never placed on the scales to be weighed. After all they arrived on the screen mere seconds after the message they're a reply to.
And still we persist. There's something with written words. It has to be absolute, to represent every aspect of what we can read into them. In ways we expect them to define the writer as a person to a much greater degree than we would if they were spoken.

So to my conclusion. Sometimes writing is indeed speaking, and we as readers have a responsibility to understand that. Or we'll simply be unable to understand at all.