It is no wonder therefore, if _Voice_ be natural to a Man, though he be _Deaf_, because _Deaf Men_ Laugh, Cry out, Hollow, Weep, Sigh, and Waile, and express the chief Motions of the Mind, by the _Voice_ which is to an Observant Hearer, various, yea, they hardly ever signifie any thing by Signs, but they mix with it some _Sound_ or _Voice_. Thus the Exclamations of almost all Nations are alike; [_a_] is the _Sound_ of him chiefly, who rejoyceth; [_i_] of him who is in Indignation, and Angry; [_o_] of one in Commiseration, or Exclamation; not to mention many such other-like.
Now I shall briefly declare, wherein the nature of the _Voice_ consisteth, where it is formed, and how it is formed: I shall also discover, together therewith, wherein is the difference betwixt _Voice_ and _Breath simply_, as what is in truth, of so much weight, that if it be unknown, some Deaf Persons cannot learn to speak, as shall be taught in the Third Chapter. Men ordinarily speak after two manner of ways, viz. either when they may be heard by any one, who is not too far distant from them, and that is properly call'd _Voice_; or else, when they speak privately in another's Ear, and then they pronounce a _Breath which is simple, but not Sonorous_. Deaf Men also do know a _Voice_ to be different from a _Simple Breath_; for they can speak both ways, and I also have learned this Distinction partly from them.
The Humane _Voice_ is Air, impregnated, and made Sonorous by the impressed Character of the Life, or is such, as whilst it is in breathing forth, doth smite upon the Organs of the _Voice_, so, as _they tremble thereupon_; for indeed, without this tremulous Motion, no _Voice_ is made: Yea, not only the _Larynx_, or Wind-pipe, doth thereupon tremble, but the whole Skull also; yea, and sometimes _all the Bones_ _of the whole Body_, which any one may easily find in himself, by his applying his Hand to his Throat, and laying it on the top of his Head. This trembling is very perceptible in most sounding Bodies, and is (if I mistake not) owing for the most part to the _Springiness_ of the Air; which, did I not study to be brief, I could more fully explicate. Now the _Simple Breath_ is Air, breathed forth by the opening of the Mouth or Nostrils, simply, and without any smiting on the parts, which rather exciteth a whispering than a sound. Hence is it, that Animals, whose Wind-pipe is cut beneath the Throat, do indeed render a _Breathing_, but no _Voice_; for the Tube of the Wind-pipe is too large, and too smooth, than that the Air can strike upon it any where; and being thus reflected on its self, it can also imprint a tremulous Motion on its neighbouring Bodies: This the Physicians Pupils do know; who being about to dissect live Dogs, they cut their Throats, that they may not be troubled with their barking: For _Voice_ differs as much from a _Simple Breath_, as doth that hoarse Sound, which we excite, by rubbing the tops of our Fingers hard upon some Glass or Table, which is quite differing from that same _soft whistling Sound_, which is heard when we lightly rub with the Hand the same Glass or Table.