Aristotle on voice

Aristotle saw the voice as being closely associated with the soul. In a passage from de Anima he says:

Voice is the sound produced by a creature possessing a soul (i.e., animals and man); for inanimate things never have a voice; they can be said to give voice only metaphorically, e.g., a flute or a lyre…Voice, then, is a sound made by a living animal, but not with just any part…[it] consists in the impact of the inspired air upon what is called the windpipe under the agency of the soul in those parts…not every sound made by a living creature is a voice (for one can make a sound with the tongue, or as in coughing), but that which causes the impact must have a soul, and accompany it with some phantasm (mental image); for the voice is a sound which is the sign of something (Wollock, 1997, p. 8)

Aristotle’s book Problems or Problema asks questions about voice, and then offers an answer. The items below are from Aristotle’s Problems (1961, translation). Problems, Section XI Loeb edition, translation by W. S. Hett, Vol 1 and one item from Vol 2. The topics are added. All but one comes from chapters 10 and 11 of Problems, volume 1. The chapter is called: “Problems connected with the voice.” There are a number of problems on hearing and on stuttering that I have not included below.

Variety of voice Chapter x paragraph 38. Why does man show great variety of voice, but other animals have only one, unless they are of different species? Or has man only one voice, though many varieties of speech?
Relationship between hearing and voice Chapter xi paragraph 1. Why do those who suffer from birth from any defective sense mostly have bad hearing? Is it because both hearing and voice may be held to arise from the same source? Now language, which is a kind of voice, seems the easiest thing to destroy and the most difficult to bring to perfection. There is evidence for this in the fact that after birth we are unable to speak for a long time, for at first we cannot talk at all, and then later for a time we falter in speech. But because language is easily destroyed, and the source is the same both of language (for it is a kind of voice) and of hearing, hearing is therefore the most easily destroyed of all the senses, not of itself but incidentally. We can find proof of this also from the other animals, that the origin of the language is quite easily destroyed, for none of the animals except man speaks, and man only does so after a time, as we have said.
Nasality of deaf Chapter xi paragraph 2. Why do the deaf always speak through their nose? Is it because deafness and dumbness are closely allied? Now the dumb make sounds through their noses, for the breath strikes through the nostrils because the mouth is closed. It is closed because they do not use the tongue to modulate the voice.
Nasality of deaf Chapter xi paragraph 4. Why do the deaf all speak through their noses? Is it because the deaf breathe more violently? For they are near to being dumb. The passage through the nostrils is therefore distended by the breath, and such people speak through their noses.
Nasality of deaf Chapter xxxiii paragraph 4 (vol 2) Why do the deaf usually talk through their noses? Is it because with them the lung has been affected? For deafness is really a congestion in the region of the lungs. So the voice does not travel easily, but as the breathing of those who puff and pant accumulates because of their lack of strength, so is the voice with the deaf. So it is forced out through the nostrils. As it is forced out it makes a noise due to the friction. For talking thought the nose occurs when the upper part of the nose, where the holes are leading to the roof of the mouth, becomes hollow; than it echoes like a bell because the lower part is narrow.
Internal temperature and vocal intensity Chapter xi paragraph 3. Why are the warm by nature always loud voiced? Is it because there must be much cold air in them? For the hot breath attracts the air to itself, the more so the hotter it is. But a loud voice occurs when much air is moved, a shrill voice when the movement is quick, and a deep voice when the movement is slow.
External temperature and frequency Chapter xi paragraph 17. Why are voices deeper in winter? Is it because the air is thicker at that time, both that within us and that without? As it is thicker, its movement is slower, so that the voice is lower. Moreover, we are more inclined to sleep in the winter than in the summer and for a longer time; and after sleep we are heavier. At the time, then, when we sleep for a longer time than are awake (that is in the winter), the conditions are the opposite. For in the short time between when we are awake, the condition established in sleep persists and inclines to sleepiness.
Vocal quality and seasons Chapter xi paragraph 56. Why do men speak more shrilly in the winter and when they are sober, but in a deeper voice in the summer and when they are drunk? Is it because a more rapidly traveling voice is shriller, and the voice which comes from that which is in a state of tension is swifter? With the sober and in winter the body is more set than with the drunk and in summer. For heat and warmth relax the body.
Vocal quality and seasons Chapter xi paragraph 61. Why are voices deeper in the winter? Is it because the air is thicker, and when it is thicker the movement is slower, so that the voice is deeper? Or is it because the air travels more slowly through narrow channels and the region about the larynx is obstructed by the cold and the phlegm flowing into it?
Food and temperature and frequency Chapter xi paragraph 18. Why do men speak in a lower key after drinking, vomiting, and in cold weather? Is it because of the obstruction of the pharynx due to phlegm? For it causes fluid matter to collect in it; for in the first case the vomiting or drinking and in the other season of the year and consequent filling make the pharynx narrower, so that the passage of breath is slower. And the slow passage causes a deep voice.
Food/drink and vocal quality Chapter xi paragraph 12. Why does the voice crack most easily after food? Is it because that part of the body grows hot because it is frequently struck, and when heated it attracts the moisture; this moisture becomes more in quantity and more easily available owing to the application of food.
Food/drink and vocal quality xi 39. (281). Why do leeks assist clear speech, since we find this true even with partridges? Is it because, whereas boiled garlic produces smoothness, leeks have a certain glutinousness. This cleans out the larynx.
Satiation and vocal quality Chapter xi paragraph 46. Why is the voice of the drunken more cracked than that of the sober? Does their voice crack quickly because they are filled? There is evidence for this; for neither choruses nor actors rehearse after breakfast, but when fasting. But as men in drink are fuller, their voices naturally break more.
Shouting after eating spoils the voice Chapter xi paragraph 22. Why does it spoil the voice to shout after food? We can see that all who practice voice production, such as actors, chorus-singers and the like, perform their exercises in the morning and fasting. Is the ruin of the voice nothing but spoiling that region through which the breath passes out? So those who suffer from sore throat have spoiled voices, not because the breath which produces the voice is in any way inferior, but because the vocal chords are roughened. This region is by nature most easily roughened by excessive heat. Consequently neither those who are feverish nor those who hae just recovered from violent fever can sing after the abatement of the fever; for their pharynx has been roughened by the heat. But after food it is natural that the breath should be considerable and hot; and it is reasonable to suppose that such breth, as it passes out, should make the windpipe sore and rough; so when this occurs the voice is naturally spoiled.
Emotions and voice—laughter and crying Chapter xi, paragraph 13. Why do those who weep speak in a shriller voice, but those who laugh in a deep one? Is it because the latter through their weakness only move a little breath, but the former exhale violently, which makes the breath come fast? But speed involves shrillness; for that which is hurled from a body under strain travels fast. The laughter on the other hand is in a relaxed state. The weak make shrill sounds; for they move but little air, and sometimes only on the surface. Laughers also exhale hot breath, but those who weep (just as pain causes a chilling of the region about the chest) exhale a colder breth. Now heat moves much air, so that it travels slowly, ut cold only a little. This also happens with pipes; for those who play with hotter breath pipe is much lower note.
Emotions and vocal quality Chapter xi paragraph 15. Why do those who weep speak with a shrill voice, but those who laugh with a deep one? Is it because those who weep strain and contract the mouth when they speak? Owing to the strain the air in them moves quickly and travels more rapidly because it passes through a narrower mouth; for both these reasons the voice becomes shrill. But those who laugh do so by relaxing the strain and opening their mouths. As, therefore, they drive the air through a wide opening slowly they naturally speak with a deep voice.
Emotions and vocal quality Chapter xi paragraph 50. Why do those who laugh utter a deep sound, but those who weep a shrill one? Is it because the voice which comes from those who are in a state of strain is shrill, and a shrill voice is weak? Both these conditions are present with those who weep; for those who weep are more under strain and weaker.
Age and pitch Chapter xi paragraph 14. Why do boys and other young animals speak on a shriller note than the fully developed creature, and that too although shrillness implies violence? Is it because the voice implies movement of air, and the quicker it travels the shriller it is? A little air moves more easily and more quickly than a great quantity, for it moves either when it is collected or dissipated by heat. Since, then, inhaling is the drawing in of the cold, the air which in us would be absorbed in it; but exhalation, when heat sets the air in motion, would become voice; for we speak when exhaling, not when inhaling. since, then, the young are warmer than the old, and have narrower channels in them, they would have less air in them. Since, then, that which is moved is less, and the heat which causes the movement in them is greater, the movement of the air would be faster for both these reasons; and the quicker moving air is shriller for the reasons given above.
Age and vocal quality Chapter xi paragraph 24. Why is it that the young of all other animals and infants have shriller voices than the developed creature, but that calves sound a lower note than oxen? Is it because in each genus the infant is similar to the female element in it? Among cattle the female sounds a lower note than the male, and calves resemble the female more than the male. But in other animals the reverse is true.
Man vs animals re vocal development Chapter xi paragraph 57. Why does the voice among men come to perfection later than in any other creature which makes a sound? Is it because in the case of man the voice has the greatest number of differences and forms? The other animals pronounce no letters or very few. Now what is most variable and has the greatest number of different forms must develop in the longest time.
Productivity and frequency Chapter xi paragraph 16. Why do the unproductive, such as boys, women and those who are quite old and eunuchs, speak with a shrill voice, but men with a deep voice? Is it that just as a line and other unsubstantial things have only one dimension but solid bodies have more, so a thin voice has only one dimension? Now it is easier both to create and to move one thing than several. As, then, with the persons enumerated above, the breath is weak, it only moves a little air. But that which has only one dimension is very small in quantity, since it will be thin for the reason given above. The voice which comes from it must necessarily be of the same kind; but a thin voice is shrill. This is why the unproductive have shrill voices; but men, being strong in breathing power, move much air, and being in great quantity it must move more slowly and produce a deep voice. For a thin and swift movement produces a shrill voice, neither of which qualities exist in the case of a man.
Age and vocal quality Chapter xi paragraph 34. Why do the unproductive, such as boys, women, and men in old age and eunuchs, speak in a shrill voice, but men in a deeper one? Is it because of the weakness of that part which moves the air? For what is weak moves but little air, but a little air travels fast and what travels fast is shrill. Or is it because the first channel through which the voice travels is small in the case of the unproductive, and so that which expels the air from it is small, and the air, being small in bulk, travels quickly through the wide upper larynx; but with those in the prime of life and adults this is distended (like the passage to the testicles), so that the air driven through is more? Since then it passes through more slowly it makes a deeper sound.
Age and vocal quality Chapter xi paragraph 62. Why do children, women and eunuchs and old men speak in a shrill voice? Is it because a shrill voice implies a faster movement? Now the same thing in larger quantity is move difficult to move, so that those who are in the prime of live draw in more air; this therefore traveling more slowly produces a deeper voice. But in children and eunuchs, because they have less breath, the opposite effect takes place. Because old men have not control they tremble, just as with weak persons and children, when they seize a long plank by the end, the other end quivers because they cannot control it. (This is why old men tremble because they no longer have control.) This same thing must be assumed in the nervous, the frightened and the shivering as the cause of the trembling of the voice. For in one whose voice is in this state, since most of the heat has collected within as a result of such conditions, the rest being small in quantity cannot control the voice; hence it shakes and trembles. This is why artists who are conscious that they are nervous speak in a low voice to begin with, and until they have settled down; for they can control the voice more easily when it is low.
Strength and pitch Chapter xi 21. Why do those who have taken exercise and weak persons speak in a shrill voice? Is it because the weak move but little air, and a little air travels more quickly than a larger quantity. But those who have taken exercise cause a violent movement in the air and violently moved air travels more quickly. And rapid movement in voice implies shrillness.
Man vs animals and vocal quality Chapter xi paragraph 40. Why do all other creatures make shriller sounds the more vehement they are, but man when he is weak? Is it because he moves less air, but this travels quickly and what travels quickly produces a shrill sound?
Transmission of voice Chapter xi paragraph 23. Why is it that, since voice is air which has taken shape and is traveling, the shape is so often dissolved, but echo, which occurs when air in this condition strikes something hard, is not dissolved, but we hear it clearly? Is it because it is refracted and not scattered? Consequently the whole persists, and two similar shapes arise from it; for refraction occurs at a similar angle. Hence the sound of the echo is similar to the original sound.
Shapes of echoes Chapter xi paragraph 51. Why does the voice, since it is only air which has assumed a shape, often lose its shape as it travels, but an echo, which occurs when air in this condition strikes something hard, does not lose its shape, but we hear it distinctly? Is it because an echo is a refraction and not a dispersion? So it returns to us whole. Again, the refraction is similar to the source from which it proceeded; for it is refracted from the air in the hollow and not from the hollow itself.
Emotion and pitch Chapter xi paragraph 32. Why do men who are anxious speak in a low voice, but those who are afraid in a shrill one? Is it because the region of the heart grows cold when men are afraid, because the heat rushes downwards, so that they move but little air? For the motive power lies n heat; but in those who are anxious heat rushes upwards, as it does with those who are ashamed; for men grow nervous through shame. When they are ashamed the heat travels up as far as the face; this is proved by the fact that they grow more red. This dissolves and thickens the air by which they speak; and air of this kind is pushed out slowly; but slowness in the voice implies deep voice.
Fear and vocal quality Chapter xi paragraph 53. Why do men speak in a deeper voice when nervous, but in a shriller voice when afraid? Yet shame is a kind of fear. Or is it really a very different affection? For those who feel shame blush (nervousness is shame in a sense), but the frightened grow pale. So it is obvious that with the frightened the heat leaves the upper regions, so that the breath being weak moves but little air, but that which is small travels fast, and what is fast in voice is shrill; but in those who feel shame the heat about the chest rises. This is proved by the fact that they blush. But a considerable force moves much air, and a great mass travels slowly, and what is slow in voice is deep.
Hearing and breathing Chapter xi paragraph 41. Why do we hear more clearly when we check the breath than when we exhale? This is why in hunting they advise one not to breathe. Is it because when the veins are distended the perception mounts upwards? For when we are asleep it descends. This is why men asleep exhale more than they inhale, and do not hear. Or does the blood also mount when we exhale, so that the parts below are emptied? For we hear in a void. Or is it because breathing itself is a sound, and when this takes place in exhaling it prevents one from hearing?
Hearing, breathing and yawning Chapter xi paragraph 44. Why do men hear less when they yawn? Is it because they check the breathing, and the checked breath collects about the ears? There is evidence for this; for when we yawn, there is a sound in our ears. But the checking of the breath prevents us from hearing. Moreover, there is a noise made by those who yawn; and this prevents them from hearing. The distention of the mouth also must contract the hearing.