Is stream-of-consciousness writing actually speech without sound?
Can one speak without sound?
A speaker is entirely connected to his speech, present at every utterance of every syllable. The stream-of-consciousness writer maintains the same tight connection, sans syllables.
I hypothesize that even without vocal chords, one still "speaks." For if we said that a person who lacked the ability to form words with his mouth couldn't speak, then we would have no choice but to say that this person could only communicate by "writing things down." We would say, "He is not a speaker, he is a writer."
However, "writing" carries its own meaning. Writing has a design, an audience, a style, a tone: elements which require a writer to think ahead, to envision a greater work that lies beyond the few sentences that might be on his page or computer screen at a given time. Writing for the sole sake of communicating or transcribing information directly from the brain has none of this intention. This type of writing only requires a person to think about the near future, the next element in the flow. Therefore, this type of writing is more like speech than like "writing" as a "writer" writes.