Aristotle · a new plain-English translation from the original language
1| Book 11: Problems Concerning the Voice Why is it hearing, above the other senses, that people are most often impaired in from birth? Is it because hearing and voice would seem to come from the same origin? Speech, being a form of voice, seems to be destroyed most easily of all, and to be brought to completion with the greatest difficulty. A sign of this is that for a long time after birth we are speechless; for at first we do not talk at all, and then, late, we begin to lisp. Because speech is easily destroyed, and both it and hearing have the same origin (for hearing too is in a sense a kind of voice, or at least something that goes along with it), hearing is destroyed most easily among the senses, and not in its own right. One can take evidence of this from the other animals too, that the origin of speech is entirely easy to destroy: none of the other animals talks except man, and even man does so only late, as has been said. Why do all deaf people speak through the nose? Is it because they are close to being mute? The mute speak through the nose, for it is by this route that their breath escapes, because their mouth is shut. And it is shut because they make no use of the tongue for voice.
2| Why are all people who are hot by nature loud-voiced? Is it because there must also be much cold air in them? For hot breath draws air to itself, and the more heat there is, the more air it draws. And loud voice arises from moving much air, and high pitch from moving it quickly; low pitch arises from moving it slowly. Why do all deaf people speak through the nose? Is it because the deaf breathe more violently? For they are close to being mute. So the passage of the nostrils is forced apart by the breath; and such people speak through the nose. Why are sounds more audible at night? Is it because there is more stillness, owing to the absence of the hottest thing? For this reason things are also generally less disturbed. For it is the sun that causes motion.
3| Why do voices seem higher-pitched from far away? At any rate, those who imitate people who are very far off and shouting speak in a high pitch, resembling those who echo, and the sound of an echo seems higher-pitched. And the echo is from far off, for it is reflected back. So then, since in sound the quick is high-pitched and the slow is low-pitched, voices ought to appear lower in pitch from far away. For again, everything in motion moves more slowly the farther it is from its starting point, and in the end falls. Is it then because those who imitate imitate with a faint voice, and the voice from far off is thin? A thin voice cannot be low-pitched, nor can something spoken small and faint be low-pitched — it must be high-pitched. Or is it not only that the imitators imitate for this reason, but that the sounds themselves actually become higher-pitched? The cause is that it is the moving air that produces the sound; and just as at first the thing that set the air in motion makes the sound, so again the air itself must do this in turn, and there must be one part moving and another being moved. That is why sound is continuous — because a moving part always hands off to a moving part, until it wastes away, which in the case of bodies corresponds to falling, when the air can no longer push — in one case the missile, in the other the air.
4| For continuous voice arises from air being pushed by air, whereas a missile is carried as a body moved by air. In the latter case, then, it is always the same body that is carried, until it falls; in the former, it is always a different portion of air. And the first, smaller portion moves faster but only a little way. That is why voices are higher-pitched and thinner from far off — for what moves faster is higher-pitched, as has also been raised as a difficulty. It is the same cause by which children and the sick speak in a high pitch, while men and the healthy speak low. The reason the voice is not noticeably becoming lower or higher in pitch to those nearby, and in general does not behave like thrown weights, is that a thrown object is a single thing always carried as the same thing, whereas sound is air being pushed by air. That is why the one falls in a single spot, while the voice spreads everywhere — as if the thrown object, while being carried, were at the same time shattered without limit, and even backward. Why do newly plastered houses echo more? Is it because reflection occurs more, owing to smoothness? They are smoother because of being unbroken and continuous. But the plaster must be taken not entirely wet but already dry; for there is no reflection from mud. For this reason plastered surfaces also echo more. Perhaps the stillness of the air also contributes something; for air moving as a mass strikes back more forcefully against what meets it.
5| Why, if someone buries a jar and empty earthenware vessels and covers them, do the rooms echo more, and likewise if there is a well or a cistern in the house? Is it because, since an echo is a reflection, the air must be gathered together in a mass and have something to be reflected from, striking upon what is dense and smooth? For this is how an echo comes about best. Now the well and the cistern provide narrowness and concentration, while the jars and earthenware vessels provide the density of what surrounds the air, so that the effect results from both. Hollow things also echo more; that is why bronze echoes most of all other materials. And there is nothing strange in the fact that they are buried; for the voice travels downward no less than elsewhere — indeed in general it seems to travel everywhere and in a circle. Why does it echo more if one buries the vessels than if one does not? Is it because, being enclosed on all sides, they receive the air into themselves and hold it more? It also happens that the blow becomes more forceful. Why does cold water poured out of the same vessel make a higher-pitched sound? Is it because its motion is faster? For it is heavier, and the faster motion makes the sound higher-pitched. Hot water, on the other hand, is made lighter both by its rarity and by its tendency to rise. Something similar is seen in the fact that burning torches, too, produce a weaker blow.
6| Why is the voice rougher in those who have gone without sleep? Is it because the body is moister on account of indigestion, and not least around the upper region, which is why there is also heaviness in the head? And since there is moisture around the windpipe, the voice must also be rougher. For the roughness is due to the unevenness, and the deepness is due to the blockage; for the passage of the air is slower. Why does the voice break most quickly after food? Is it because the region, being struck, is heated, and being heated draws in the moisture? And this moisture is more abundant and readier because of the taking of food. Why do those who weep cry out shrilly, while those who laugh cry out deeply? Is it because the former move little breath, owing to weakness, while the latter move it violently, which makes the breath travel fast? And the fast is shrill; for a thing hurled from a body under tension travels fast too. But the laugher moves it in the opposite way, loosely; the weak, by contrast, produce a shrill sound, for they move little air, and that only near the surface. Further, those who laugh let out warm breath, while those who weep — just as grief is a chilling of the region around the chest — let out colder breath. Now the warm moves much air, so that it travels slowly, while the cold moves little air. This happens with pipes too; for those who play the pipe with warmer breath play it much more deeply.
7| Why do children and the young of other animals cry out more shrilly than full-grown ones, even though shrillness consists in violence? Is it because voice is a motion of air, and the faster motion is the shriller? And a small quantity of air is moved more easily and more quickly than a large one. It is moved either by being compressed or by being separated out under the action of heat. Since inhalation is an intake of cold air, the air within us would be compressed during it; but exhalation, in which heat sets the air in motion, would produce [the] voice — for we produce voice by exhaling, not by inhaling. Now since the young are hotter than the older and have narrower passages within themselves, they would have less air within them. And since what is moved is less, and what moves it — the heat — is greater in them, the motion of the air would come about faster on both accounts; and the faster motion would be shriller-voiced, for the reasons already stated. Why do those who weep cry out shrilly, while those who laugh cry out deeply? Is it because those who weep produce their voice by straining and drawing the mouth together? By this very tension the air within them is moved fast, and by traveling through the narrow mouth it travels faster still; so on both accounts the voice becomes shrill. Those who laugh, on the other hand, laugh with the tension relaxed and with the mouth gaping open. Sending out the air broadly and slowly in this way, they naturally speak in a deep voice.
8| Why do the unproductive — for instance children, women, and old men already advanced in years, and eunuchs — cry out shrilly, while men cry out deeply? Is it that, just as a line and other thin things have a single dimension while thick things have several, so too a thin voice would have a single dimension? And it is easier both to produce and to move one thing than several. Since the beings just mentioned have weak breath, they move with it only a little air. And the least air is that which has a single dimension, which will be thin for the reasons stated; and the voice arising from it is of the same character, and a thin voice is shrill. The unproductive, then, are shrill-voiced for these reasons; but men, being strong in breath, move much air, and a large quantity, being moved slowly, produces a deep voice. For it was thinness together with fast motion that produced a shrill voice, and neither of these occurs in the case of the man.
9| Why are our voices deeper in winter? Is it because the air is thicker then, both the air within us and the air outside? And since it is thicker, the motion becomes slower, so that the voice is deeper. Further, we are more inclined to sleep in winter than in summer, and we sleep for a longer time; and coming out of sleep we are deeper-voiced. In the season, then, in which we sleep more than we are awake — and this is winter — we would be deeper-voiced than in the season of the opposite condition. For since the time between waking is short, the state produced during sleep persists close up to the time of falling asleep again. Why do people speak in a deeper voice after drinking bouts, after vomiting, and in cold weather? Is it because of the blockage of the throat brought about by phlegm? For it draws a little flux down into it; and in some cases the vomiting or the drinking, in others the season and the fullness of the body, makes the throat narrower, so that the passage of the breath becomes slower. And the slow passage also produces a deep voice.
10| Why is the deeper voice heard better from nearby, but less well from far off? Is it because the deeper voice moves more air, but not so as to reach far? From far off, then, we hear it less, because it is moved over a smaller distance; from nearby we hear it more, because more air strikes our organ of perception. The shrill voice, by contrast, is heard far off, because it is thinner, and the thin has the capacity for extension in length. One might also say that the motion producing it is faster. And this would be the case if the breath moving the air were dense yet narrow. For a small quantity of air is more easily moved (since a small quantity is moved by a narrow stream), and density produces more strokes, and these produce the sound. This can be seen in instruments: the thinner strings are shriller, other things about them being equal. Why does the voice appear shriller to those standing farther away, when shrillness consists in traveling fast, while what travels farther moves more slowly? Is it because the shrillness of a voice consists not only in moving fast, but also in the sound becoming very thin? And to those standing farther away the voice that arrives is always thinner, because of the smallness of the quantity of air being moved. For the motion dies away, and as it dies away the number ends at the one, and the body ends at a single dimension, which in a body is thinness. And it is the same with voice.
11| Why do both those who have exercised and those who are weak cry out shrilly? Is it because the weak move little air, and a small quantity travels faster than a large one, while those who have exercised move the air strongly, and air moved strongly travels faster? And what is fast in travel is shrill in voice. Why is the voice ruined in those who shout after meals? And we may observe all who train the voice — actors, chorus members, and others of this kind — making their exercises early in the morning and while fasting. Is it that for the voice to be ruined is nothing other than for the region through which the breath passes to be damaged? This is also why those with sore throats have their voices ruined — not because the breath that produces the voice becomes worse, but because the windpipe has been roughened. And this region is naturally roughened most of all by intense heat. This is also why neither those with fever nor those who have just recovered from a severe fever can sing right away; for their throat has been roughened by the heat. And it is likely that the breath arising from food is both abundant and hot; and it is reasonable that such breath, passing through, ulcerates and roughens the windpipe. And when this happens, it is reasonable that the voice is ruined.
12| Why is it that, if voice is a shaped and moving mass of air, its shape is often dissolved, yet the echo — which occurs when such air strikes something solid — is not dissolved, but we hear it clearly? Is it because this is reflection, not refraction? In this way the whole persists, and two parts of like shape arise from it; for the reflection occurs at an equal angle. That is also why the sound of the echo comes out like the original. Why is it that among the other animals the young and immature call out more shrilly than the full-grown, but calves call more deeply than full-grown cattle? Is it because in each kind the immature resembles the female of that kind? Now among cattle the females call more deeply than the males, and calves are more like the females than the males; but in the other animals it is the opposite. Why is it that when the orchestras are strewn with chaff the choruses are heard less well? Is it because, striking against the roughness rather than a smooth floor, the voice becomes less unified, and so weaker? For it is not continuous. Just as light, too, shows up more on smooth surfaces, because it is not broken up by obstructions.
13| Why is it that salt, when thrown into fire, makes a noise? Is it because salt has some moisture in it, not much, which, turned to vapor by the heat and forced out violently, splits the salt apart? And everything that is split makes a noise. Why is it that some children, before reaching the age proper for speaking clearly, utter sounds and even say things clearly, and then go back to behaving as before, until the usual time arrives? Many people think these cases are prodigies. Indeed some are even said to have spoken right at birth. Is it because, as a rule, most things that come to be come to be according to nature, which is why this happens to only a few, and by nature the corresponding parts reach completion together? That is why a child hears and speaks at the same time, and understands by hearing, and talks, and speaks clearly, all together. Yet often the same parts do not keep pace with each other: some children understand before the part by which they speak is set free for use, and in others the reverse happens. Now the ones who understand first would not converse intelligently (for they converse only in what they have heard [and repeat]); but when the right time comes for both together, they render what is according to nature. But in those in whom the sense connected with hearing becomes precisely tuned in the soul earlier — the sense by which they first set the voice in motion and produce speech — it sometimes happens, once they already understand many things, that a certain capacity and release of that part occurs, especially after some sleep (the reason being that sleep makes the body more sluggish too, and, by resting the parts, [releases them]); and if not after sleep, then after some other such change.
14| We are capable of doing many such things, which need only brief occasions; and then the part is no longer in the same state, once it happens to be disposed and released in that way; when the thought that set it in motion is still on the surface of perception, it comes back by way of hearing, and the child speaks. Often, too, tunes and phrases come over us not from deliberate choice; but if we say something the first time by choice, later we say it or sing it without choosing to, and it cannot help but come out of the mouth. It is the same with children: when this happens to come upon them, that part then settles back into its natural state, until the time comes for it to grow strong and be set free for good. Why is it that some things make a noise and move suddenly, chests for instance, when nothing perceptible is moving them? And yet what moves them must be stronger than what is moved. The same account applies to decay and old age too; for everything that is called being destroyed by time is destroyed by something imperceptible. Or is this like the case of drops of water, and of stones lifted up by things growing beneath them? For it is not the last drop that lifts or moves the thing, but the continuous process. And in this case, though it is imperceptible, the motion happens to become perceptible. In the same way, what is bounded by perceptible stretches of time also moves, and is divided into imperceptible parts, but as a whole and continuous process it produced motion and decay. And what is continuous is not in the now, but in the time that is marked off by the now.
15| Why is it that people who are yawning hear less well? Is it because a great deal of the breath going out in the yawn passes also into the ears from inside, so that the motion it produces around the hearing is noticeable even to perception — most of all right after sleep? Now sound is air, or an affection of air. So when the sound from inside strikes back, the sound from outside enters against it, and by the motion and the sound from outside the inner motion is knocked out. Why is it that people stammer more as children than as men? Is it not just as children always have less control of their hands and feet, and those who are too small cannot walk — likewise the younger cannot control the tongue either? And if they are altogether small, they cannot even speak at all, but only cry out like the animals, because they lack control. And this would apply not only to stammering but to lisping and slurring too. Now lisping consists in not controlling some letter — and not just any letter — while slurring consists in dropping something, either a letter or a syllable, and stammering comes from not being able to join one syllable quickly to another. All of these come from a kind of incapacity; for the tongue does not serve the thought. Drunk people and old people suffer this same thing too, though in all of them it happens to a lesser degree.
16| Why does the voice tremble in people who are in anxious contests and in people who are afraid? Is it because the heart shakes as the heat goes out of it? And this happens in both cases; for it occurs both to people in anxious struggle and to people who are afraid. When it shakes, the striking of the air does not happen as a single blow but as several, like the striking of loosened harp-strings. Why is it that people in anxious contests speak in a deep voice, while people who are afraid speak in a high voice? Is it because in those who are afraid the region around the heart is chilled, as the heat rushes downward, so that they move only a little air? For strength lies in heat. But in the others the heat is carried upward, as it is in people who feel shame; for people in anxious contests feel a kind of shame too. In those who feel shame the heat is carried upward toward the face — the sign of this being that they turn redder. So it melts and thickens the air by which they speak; and such air is pushed along slowly; and what is slow is deep in voice.
17| Why is the night easier for hearing than the day? Is it, as Anaxagoras says, because by day the air, heated by the sun, hisses and makes a noise, while by night it is quiet, since the heat has departed, and a thing is more audible when nothing else is making noise? Or is it that a thing is more audible through what is emptier rather than through what is full? By day the air is dense, since it is filled by light and by the sun's rays, but by night it is more rarefied, because the fire and the rays, being bodies, have departed from it. Or is it that by day bodies draw the mind toward many things, and so it is not sharply focused for hearing? And this is also because we do all our activities by day rather than by night, and our attention is bound up with those activities. Perception cut off from thought is like an imperceptible exertion — as has been said, it is the intellect that sees and the intellect that hears. At night, since sight is idle and thought is more at rest, the passage of hearing, though it is open just as it is by day and equally receptive of sounds, reports them more fully to the thought, because thought is neither active on its own account nor disturbed by sight, as it is by day.
18| Why do those who cannot beget children — for instance children, women, old men already, and eunuchs — utter a high-pitched sound, while men speak more deeply? Is it because of the weakness of the part that moves the air? For what is weak moves only a little air, and a little air is carried quickly, and what is carried quickly is high-pitched. Or is it because the first passage, through which the voice is carried, is small in those who cannot beget, so that what pushes the air out of it is little, and being little it is carried quickly through the wide upper throat? But in those in their prime and grown to manhood this passage widens, just as happens also with the testicles, so that what is pushed is also greater in amount. Passing through more slowly, then, it becomes deep. Why can those who stammer not converse quietly? Is it because they are checked in speaking by something that obstructs them? Now when the strength is not equal, nor the motion similar, one must force one's way through when nothing obstructs the motion and also when something does obstruct it. The voice is a motion; and those who use their strength utter a louder sound. So, since it is necessary to force out by violence what obstructs, it is necessary that stammerers speak more loudly. Why do people become more prone to stammering when anxious, but less so when drunk? Is it because the condition is like a stroke affecting some internal part, which they are unable to move, since it is obstructed on account of a chilling? Wine, then, being hot by nature, dissolves the chilling more, while anxiety produces it; for anxiety is a kind of fear, and fear is a chilling.
19| Why is sound heard better going from outside into houses than going from inside outward? Is it because sound coming from inside is torn apart as it travels through the open expanse, so that each part is not enough to be heard, or is heard less? Whereas sound going from outside inward, traveling into a smaller space and into still air, arrives massed together, so that being greater it is heard better. Why are stammerers melancholic? Is it because to follow one's imagination quickly is exactly what being melancholic is, and stammerers are of this sort? For in them the impulse to speak outruns their capacity, since the soul follows what appears to it too quickly. And lispers are the same way; for these people's parts are shorter. Here is a sign: people become like this when drunk, at which time they follow what appears to them most of all, and not their intellect. Why do leeks contribute to a good voice, since they also help partridges? Is it because garlic too, when boiled, smooths the throat, while leeks have a certain stickiness, and this cleanses the throat? Why do other creatures utter a higher-pitched sound the more vehement they are, while a man does so when he is weak? Is it because he moves less air, and this passes through quickly, and what is quick makes the sound high-pitched?
20| Why do people hear better when holding their breath than when breathing out? This is why in hunting men warn one another not to pant. Is it because the sense-organ moves upward as the veins are raised? For in sleepers it moves downward; that is also why sleepers breathe out more than they breathe in, and are hard of hearing. Or is it also that the blood moves upward when a person has breathed out, so that the lower parts are emptied? And people hear by means of the empty space. Or is it because breathing itself is a kind of noise, and this noise, occurring during exhalation, prevents hearing? Why do small grains of salt crackle and leap sooner, but large grains crackle and leap more loudly? Is it because the small ones split quickly — for there is not much for the fire to pass through — owing to their smallness, while the large ones split slowly, since splitting a larger thing is a greater task than splitting a small one? And the small grain makes a small sound, since the blow is small, while the larger one makes a loud sound, since the blow is great; and sound is a blow. And what is stronger leaps more, if it is struck, since it yields less. Why, if one throws the same amount of salt into a great fire, does it crackle less, or not crackle at all? Is it because it is burnt up before it can split? For it burns because its moisture is used up, but it crackles because it splits.
21| Why do those who yawn hear less well? Is it because they trap breath inside, and the trapped breath collects around the ears? Here is a sign: a noise occurs in the ears when we yawn. The trapped breath prevents hearing. Further, a kind of sound is also produced by people yawning, and this too impedes hearing. And the passages of hearing are necessarily compressed as the mouth is stretched wide apart. Since the voice is a kind of flow and has a nature that carries it upward, why is it heard better when it goes from above downward than from below upward? Is it because the voice is a kind of air mixed with moisture? Weighed down, then, by the moisture, it is carried downward and not upward; for the downward motion belongs to moisture by nature. That is why it is heard better by those below. Or does this happen only in the case of an animal's voice — since this is mixed with moisture — while what actually occurs holds for other sounds too? Just as with sight: if it strikes from above downward, it makes its reflection upward, while striking from below upward it is reflected downward — in the same way voice, which has a nature that carries it upward, when it strikes against the air facing it, cannot force its way through, since that air is greater in amount and heavier, but the air that has been set in motion, being reflected, is carried in the opposite direction, downward; that is why, pouring down, it is heard better below. What happens with an echo is of the same kind: it is a reflection of the voice in the opposite direction.
22| Why does the voice break more in the drunk than in the sober? Is it because they fill up quickly and so break their voice? Here is a sign of this: neither choruses nor actors rehearse right after a meal, but while fasting. In drunkenness, being fuller, they reasonably break their voices more. Why is it that higher-pitched sounds are heard from farther away? Is it because the high-pitched in a sound is quick, and things carried more by force move more quickly, while things carried more vehemently travel farther? Why do we hear better when we hold our breath? Is it because breathing itself supplies a certain noise? Reasonably, then, we hear better at that time, when the noise is less — and the noise is less when we hold our breath. Why does light not pass through dense bodies, although it is finer, travels farther, and moves faster, while sound does pass through? Is it because light travels in a straight line, so that if anything blocks the straight path it is shut out entirely, whereas sound travels and does not go straight, because it is breath? That is why we hear a sound coming from every direction, and not only sounds that lie in a straight line to our ears.
23| Why do people who laugh utter a deep sound, while people who weep utter a high one? Is it because a high-pitched voice comes from taut parts, and what is high-pitched is weak? Both of these belong more to those who weep; for those who weep are both more taut and weaker. If the voice is a kind of shaped air, and as it travels its shape is often dissolved, why is an echo — which occurs when this strikes against something solid — not dissolved, but heard by us clearly? Is it because it is a reflection, not a breaking-up? For this is a whole affecting a whole. Further, the affection comes from something similar; for it is reflected from the air in the hollow, not from the hollow itself. Why, when one person and when many people utter a sound together, is the resulting sound neither equal, nor does it carry farther in proportion to their number? Is it because each person pushes forward the air about himself, but not the same air as the others, except to a small extent? What happens is like what would happen if many people were throwing, yet each with a different stone, or most of them were. For in that case no missile will travel far, or not in proportion; and it is the same here, since the sound of that magnitude does not belong to one person but to many. So from nearby the voice appears great in proportion — for more missiles too will strike the same target — but from far away it no longer does.
24| Why do people in distress speak in a lower pitch, while those who are afraid speak in a higher pitch? And yet shame too is a kind of fear. Or does the affection differ greatly? For those who feel shame blush (distress is a kind of shame), while those who are afraid grow pale. It is clear, then, that in the fearful the heat fails from above, so that the breath, being weak, moves only a little air, and what is little moves quickly, and what is quick in the voice is high-pitched; but in those who feel shame the heat travels upward around the chest. A sign of this is that they become quite red. Now great power moves much air, and what is much moves slowly, and what is slow in the voice is low-pitched. Why do people become stammerers? Is the cause a chilling of the place where they speak, as it were a kind of paralysis of that part? That is also why, when warmed by wine and by speaking continuously, they string their speech together more easily. Why does man alone among the other animals become a stammerer? Is it because he alone shares in speech, while the others share only in voice? Stammerers do utter voice, but they cannot string speech together. Why do people speak in a higher pitch in winter, even when sober, but in a lower pitch in summer, even when drunk? Is it because the quicker voice is the higher-pitched one, and the voice from a taut source is quicker? And the bodies of the sober are more compact in winter than the bodies of the drunk in summer. For heat and warmth loosen the bodies.
25| Why is the voice the last of the vocal faculties to reach completion in human beings? Is it because it has the most differentiations and forms? For the other animals converse in no articulate sound, or in few. And what is most varied and has the most differentiations must necessarily be completed over the longest time. Why does sight not pass through solid bodies, while voice does pass through? Is it because sight has a single path of travel, the straight line (a sign of this is the sun's rays, and that we see only from what is directly opposite), while voice has many paths? For we hear from every direction. So when sight is prevented from issuing forth in a straight line, because the pores are not aligned with one another, it is unable to see through. But air, and voice, since it travels everywhere, passes through in every direction and is heard. In liquids, sight sees through, but voices are not heard, or scarcely, though the liquid is finer than earth — because its pores are small and close together and aligned with one another, so that sight is not prevented from traveling in a straight line. That is also why one sees through glass, since it is dense, but not through a fennel-stalk, since it is porous. Further, the pores of the one are aligned, those of the other are staggered; and it is no use for the pores to be large if they are not in a straight line. But voice is not heard through water, because the empty spaces in water are fewer than in air, so that it cannot receive nor let the voice pass through, except scarcely [or accompanied by voice].
26| For voice is a kind of air. For not everything that is more porous is more penetrable, unless its pores also fit what is passing through; so too a thing is not more able to draw together into itself, unless its pores are receptive of the bodies. And yet what is porous is soft and able to draw together into itself. But some things are prevented by the smallness of their pores, for example glass; for its parts are not drawn together, though it is more porous than the fennel-stalk, for the reason stated. And water is the same, and anything else of that kind; so this too is clear, that when the porous and the soft are the same, or close in nature, it is not the more porous that is more drawn together into itself; for the cause is the same in all cases. Why does the voice become smaller when certain sounds are removed, yet remain similar in character? Is it because that element was mixed in with them throughout? For what is mixed is not present in one part and absent in another, but everywhere. So when it is removed equally from every part, the whole comes together in like manner, so that the result must be both smaller and similar. Why do people become stammerers? Is it through heat that they are too impetuous, so that they stumble and check themselves, as those who are angry do? For these too become full of gasping breath. A great quantity of breath results. Or is it because of the boiling of the heat that they pant, because it is abundant and does not manage to get out in time for the moment of breathing? Or is it rather the opposite — a chilling, not a heating, of the place where they speak, as it were a paralysis of that part? That is also why, when warmed by wine and by speaking continuously, they string their speech together more easily.
27| Why are voices lower in winter? Is it because the air is thicker, and when it is thicker the motion is slower, so that the voice is lower? Or is it because air moves more slowly through narrow passages, and the region around the throat is constricted by both the cold and the phlegm that flows into it? Why do children and women and eunuchs and old men speak in a high pitch? Is it because the quicker motion is the higher-pitched one? Now the same amount of air is harder to move when there is more of it, so that people in their prime draw in more air along with the breath; and this, moving more slowly, produces a lower-pitched voice. But in children and eunuchs, because they have less air, the opposite happens. And the elderly tremble because they are unable to control it — just as with the weak and with children, when they take hold of a long piece of wood by one end, the other end shakes because they cannot control it. (That is also why the elderly tremble — because they can no longer control it.) The same cause must be supposed to account for the trembling of the voice in those who are in distress, afraid, or shivering with cold. For when a person has this kind of voice, and most of such affections have settled inside, what remains, being little, cannot control the voice; hence it shakes and trembles. That is also why skilled speakers who are aware that they are in distress speak quietly at first, until they settle down; for when the voice is small it is easier to control.