The thing about written words and spoken words are that the meanings alloted to each are different.
When something is written, the author, past having written the words has no control over who may read it and what they may interpret.
When something is spoken, I suppose it is similar, but spoken words allow the listener to comprehend what is not spoken as well. The tone of their voice, the nonchalance, the pauses for thinking.
I find I make faster decisions when someone speaks to me, I react faster to. The old suicide note, is probably the only written doc that would make me move as fast, needless to say, I have had the good fortune of never having had to read one and respond.