The words I mean to say

I enjoyed the closing piece in the NYT Book Review about the speaking ability of many writers. Gifted as many authors are when writing, many make poor conversationalist or less-than-inspiring extemporaneous speakers. The author of the piece posits that despite issuing from the same head, words for speaking and words for writing are distinct processes:

"There seems to be a rhythm to writing that catches notes that ordinarily stay out of earshot. At some point between formulating a thought and writing it down falls a nanosecond when the thought becomes a sentence that would, in all likelihood, have a different shape if we were to speak it. This rhythm, not so much heard as felt, occurs only when one is composing; it can’t be simulated in speech, since speaking takes place in real time and depends in part on the person or persons we’re speaking to. Wonderful writers might therefore turn out to be only so-so conversationalists, and people capable of telling great stories waddle like ducks out of water when they attempt to write. "