I already explored two of the ways I describe my brother on this blog: Autistic, a hot topic everywhere; low functioning (formerly known as retarded), so today’s post will be about the quality of being ‘nonverbal’.
There seems to be a range of verbality – a term I just coined. In ‘Jack’s scale’, which I also just made up, the gamut runs from being prolixity to muteness, with the following intervening states: long-windedness, verbosity, over-talkativeness, taciturnity and sullenness.
Talking too fast
In Seminars in General Adult Psychiatry, “The term ‘prolixity’ is used to described milder abnormalities of speech in mania.”  Smith and Ghaemi describe prolixity in terms of hypomania: “In hypomania, there is an increased pressure of speech with prolixity, an abnormal liveliness of expressive movements, superficial bustling activity and a tendency to be argumentative and irritable if thwarted in anyway. The patient is interested in everything, starts many projects, and finishes none . . . the elated mood leads to faulty judgment and a lack of consideration for others.” (Fish, quoted by Hamilton, 1974: p. 73).” 
It is possible that you have found yourself speaking very quickly when exuberant about a pet idea, or trying to communicate a concept about which you are passionate. There is a joy in being successful with that effort.
Normal pace of speaking
The normal pace of speaking probably depends upon the environment. If there are many fast talkers about, you must also talk fast in order to be heard. There are also occasions that require fast-talking on a one-on-one basis: 1) pitching an idea to a person who has the ability to further your goal; 2) presentation of status, update or other reports to people for whom you work. In both these cases, the target of the speech has little time and may be easily distracted. Clear speech is important, but more important are the ideas.
For me to participate in a garden-variety conversation: 1) I need to have something to add; 2) I need to think that I will be heard. Listening is a big consideration in any type of conversational speaking.
My nickname in college was ‘Slow’. I rarely contributed to conversations (aloud). I would always think about what I was going to say, think about the range of responses I would get, deem them unsatisfactory, and refrain from what I was going to say in the first place. Much of this was due to shyness, in my opinion.
Just for grins, if you ever get a chance, listen to Bob and Ray’s schtick featuring interviews with the Slow…….Talkers……of………….America. This is about as close as one comes to the lower limits of the pace of speech. Any slower, and we’re bordering on muteness.
My brother Mike is not mute. He has the anatomical equipment to vocalize, which he does. Some of his sounds seem joyful (i.e., EEEEEEEEEEEEAAAAAAAA), some seem pensive (his grunting), some I don’t know what to make of (i.e., digadigadiga).
Is speech needed for thinking?
I don’t know if my brother thinks. I don’t have a rigorous definition of ‘thinking’ on hand as I write this, but my own definition is as follows: Thinking is an internal (mental) narrative whose purpose it is to anticipate future situations and plan for good outcomes. Does one need language to do this? Maybe so, but there are other modes of language, than those that are written or spoken, such as visual and musical. Temple Grandin makes it clear that she ‘thinks in pictures’. My sense is, the connection between individual ideas, whether expressed in words, musical phrases or visual images, makes the narrative.
It is hard to imagine Mike’s internal narrative. I doubt he has a very sophisticated one. But on a very low level, he can communicate his needs to others. For instance, if he cannot open a door, he will grab someone’s hand and bring it to the doorknob of the door in question; if he wants to go for a walk, he will similarly take a person’s hand and lead him or her to the door leading outside. And once, I was a witness to this, he even learned a sign-language sign for ‘thirsty’!! This behavior quickly vanished, as if he had no use for it.
So there you have it, my brother, Mike: autistic, low functioning and nonverbal.