THE EARThe external ear is an organ for receiving and collecting the vibrations which we recognize as sound. This outer ear is composed of elastic, vibratory cartilage, covered closely with a protecting skin, and thrown into sweeping folds, no doubt conforming to the natural sweeps of aërial undulations, and designed to catch them all, coming from every direction, and conduct them to the inner ear. This is a conduction of vibrations, not of air; and it is accomplished partly by the reception of the vibrations by the cartilage itself, and partly by the reflection and concentration of these vibrations into the column of air leading into the auditory tube. No doubt the vibrations of the cartilage and those of the adjacent air make one; and, as the cartilage reflects and turns the little waves towards the inner ear, it accompanies them with sympathetic tremblings to the bony passage, and, on the under side, even half-way, through the passage; nor does it leave them till it has had time to impart its tremulous sympathy to the bone itself, with which it is strongly and closely connected.Across this bony tube, at a distance of a little less than an inch from the surface of the skull, is stretched a membrane commonly called the drum of the ear. It is really a triple membrane, composed of a fibrous layer in the middle stretched from bone to bone, covered outside by a delicate continuation of the skin which lines the tube, and inside by another delicate membrane continuous with the lining of the middle cavity of the ear. Upon this drum, or tympanum, arc concentrated all the motions which have been gathered from the atmosphere, which are now imparted to the drum by the air itself, which is in contact with it; by the lining membrane of the tube, which forms the outer skin of the drum; and by the tremblings of the bone in which the circumference of its middle layer iis inserted. The sounds that thus come to the drum of the ear are a confused mass, in immense variety as to force, pitch and quality, mingled together apparently in hopeless perplexity. It is like the stream of fluids brought to a gland — as, for instance, by the portal vein to the liver — there to be strained and sorted; the worthless to be cast out, the better sort to be put to a low use, and the pure, refined stream to be sent into the circulation for the benefit of the life of the body. In the ear the stream to be examined is not a stream of fluid, but of motion; and we must look not for open passages, but for conductors of vibrations. In the drum of the ear, with its adjacent bony wall, the expectant mass of vibrations is collected, searching for avenues of entrance. Conspicuous among these avenues is a chain of three small bones, one end of which is attached to the middle of the drum, at the point of greatest motion, and the other, in shape like the flat plate of a stirrup, is continuous as to its periosteum with another little membranous window on the opposite side of the chamber across which the chain is extended. That inner membranous window is the entrance to another chamber, properly called the inner ear, whose wonderful structure we will consider presently. The chamber crossed by the chain of bones. is called the middle car. The bones are arranged as a series of levers in such a manner that whatever motion is imparted to them by the drum is carried to the inner window with a somewhat diminished range of motion, but proportionately increased force. They seem capable of receiving and transmitting every variety and form of atmospheric tremble; but, however rapidly the tremblings may succeed one another, only one pulsation can be conveyed at a time, and thus the pulsations to be examined are in a degree strained of their conflicting elements, arranged in a sequence, and transmitted distinctly to the inner ear. Other vibrations not thus conveyed successively and distinctly by the bones, are transmitted more obscurely by the air which fills the middle ear, and also by its lining membrane and bony walls, and are received obscurely by the free rim of the membranous window to which the chain is applied, by another membranous window, called the round window, and by the bony wall of the inner ear. The most violent vibrations, which, if allowed to act with unmodified force would injure the inner ear, are as it were rejected by the way of the Eustachian tube, which leads from the middle ear to the pharynx; and perhaps are neutralized in part by the air of the large air cells in the mastoid process, which opens into the middle car opposite to the Eustachian tube. The particular stream of pulsations which shall be received by the little bones is in a considerable degree determined by small muscles, which, by pulling upon the bones, regulate the tension of the membranes, and thus tune them to receive most distinctly the sounds selected. In this, too, the ear resembles the glands, every one of which draws to itself a stream of such materials as it desires. It is in part because the ear has this power of selection that the Lord commands us, “Take heed what ye hear.” It is by the action of these muscles that we are enabled to attend to the sounds of a single instrument in an orchestra, one part in a choir, one voice in a company, an individual bird or cricket in the chorus of a summer's day; which sound thus chosen is carried to the inner ear distinctly by the chain of bones, and is accompanied obscurely by the other sounds. Arrived at the oval window of the inner ear, the current of pulsations finds ready admittance, and permeates with its successive thrills a delicate fluid which fills all the chambers of the inner ear, containing freely suspended in itself minute stony particles. And, first, it is received in a somewhat spacious ante-room, or vestibule, whose wall is loosely lined with an inner wall of membrane plentifully supplied with fibres of the auditory nerve. As the pulsations advance successively to the inner chambers, their more subtile elements will be disclosed and set free; but here at the entrance their general quality is first perceived, as to its loudness or softness, continuity or interruptions to which general perception the simple form of the anteroom is well adapted. From the part of the vestibule sometimes called the utriculus,” open three semi-circular canals. These, like the vestibule, enclose loose membranous linings which repeat their own forms, and which, in a bulb-like swelling at one end of each canal, contain a large supply of nervous fibres. At present the scientific view of these canals is that their use is not as or-ans of hearing, but as means of preserving the equilibrium. No doubt they have this use; but it is not so easy to believe that they have no part in the function of hearing. The eyes, also, in some persons, are an important means of equilibration; but no one can doubt that this is secondary to their function of sight. In the eyes, however, the assistance in preserving the equilibrium is dependent on the sight; but this service from the canals does not at all depend upon the hearing, but upon the motion of the fluid contents. The membranous canals exist in fishes, and their bony walls also in reptiles, which have scarcely a trace of the inmost part of the ear, the cochlea, which receives its full development only in warm-blooded animals, and especially in mammals. If the canals do have any part in the hearing, probably it is to distinguish articulations; for the first process in analysis should be to measure the last modification given to the tones, which, in speaking, is by the mouth in forming words. It seems as if the canals lying on three sides of a cube could measure any form that could be given by the mouth. Having received from the stream of sound the impression of force and quantity in the vestibule, and possibly of the forms of its articulations in the canals, there remain to be distinctly perceived its pitch and musical quality, and those more delicate thrills within the tones, which express the interior affection of the speakers or singers, and which are commonly attributed wholly to the “overtones,” but may in part have another origin. For this analysis, we have left an instrument of exquisite adaptation to the purpose called “the cochlea.” Into the hollow centre of a spiral staircase, resembling in its outer covering two and a half turns of a snail-shell, enters a large nerve, which extends its fibres plentifully over the elastic, bony stairs. These delicate plates of bone are attached at their inner ends to the core of the shell. At the lower part, where the diameter is large, they are long; but they diminish with the spiral to the top, like the diminishing teeth of the comb of a musical-box. At their outer end they are free, but there the membranes which cover them above and below separate, and leave a triangular space between them as they run divergently to the outer wall of the shell. In this little spiral chamber, coiled at the outer edge of the stairs, is a most delicate apparatus of nervous fibres and cells and hairs, almost too minute for the microscope, called the “organ of Corti.” We must not forget to notice that the shell is filled above and below the staircase with conducting fluid, which passes freely from one side to the other through an opening over the stairs; that the space over the staircase opens immediately into the vestibule; and that under the staircase is the membrane of the round window, communicating with the middle ear. The elastic, bony fibres of the staircase are sufficient in number and variety to harmonize in vibration with musical tones of any shades of pitch which we have the power to appreciate; and at their extremities lies an apparatus distinctly more minute and exquisite, capable of appreciating an inner music within the music, if such there may be. The organ of Corti does not exist in birds; though they undoubtedly can distinguish variations of pitch quickly and accurately. It is still a question among physiologists, whether the vibrations which are perceived as sound affect the bones and fluids of the ear as to their masses or as to their particles, — whether for example, the little chain of the middle ear is shaken as a chain, or communicates the thrills of sound by the vibrations of the particles of bone and membrane of which the chain is composed. Swedenborg believed that both motions existed, — that the larger forms of motion and of sound were communicated by the general motions of the bones and fluids, and that a more subtile tremor permeated the very substance of the bones, membranes, and fluids. The things extracted or secreted from the stream of sound by the laboratory of the ear are not fluids or solids, but motions; they are not even forms of fluids or solids, as are the impressions received by the organs of touch, taste, and smell; but they are forms of living activity. And these varieties of living motion are distinctly communicated to the fibres of the auditory nerve, and by them imparted to the brain. The portion of the brain which is the seat of the conscious reception of sounds through the ear, lies quite near, in what is called the Superior tempero-sphenoidal convolution. But an important part of the auditory nerve goes direct to the cerebellum, which is the seat of the affections of the life, and of involuntary motion, and there has a tendency to produce immediate impulsive action in response to its impulses. The optic nerves are cerebral nerves, having no direct communication with the cerebellum. They minister, therefore, primarily to the intelligence but the auditory nerves minister directly to the affections as well as to the intelligence. Probably the conscious hearing, with intelligent reception of the ideas conveyed by the sounds, is in the convolution of the cerebrum especially devoted to this sense. Other effects of warning or guidance or direction, are produced through the cerebellum, and by indirect communication with other parts of the cerebrum. “The things which enter by the sense of sight, enter into man’s understanding and enlighten him;... but the things which enters by the sense of hearing, enter into the understanding and at the same time into the will; wherefore by the hearing is signified perception and obedience. Hence it is that in human language it is a received form of expression to speak of hearing any one, and also of giving ear to any one; likewise of being a hearer, and of hearkening; and by hearing any one is understood to perceive, and by giving ear to any one is meant to obey; as also by being a hearer; and both are signified by hearkening. This form of expression has flowed down from the spiritual world, in which the spirit of man is; but whence this is in the spiritual world shall also be explained. They who, in the spiritual world, are in the province of the ear, are forms of obedience from perception;...and the province of the ear is in the axis of heaven, and therefore into it, or into those who are there, the whole spiritual world flows, with the perception that it must so be done; for this is the reigning perception in heaven; hence it is that they who are in that province are forms of obedience from perception.After describing some who seem to have been perversions of the faculty, he says that one came to him who was said to have been “a person of the highest reputation in the learned world, and it was given me to believe that it was Aristotle.” Swedenborg perceived that the things which he had written were from interior thought, and that the philosophical terms which he invented were not mere terms with him, as they were with many of his followers, but were descriptive of interior things “and that he was excited to such things by the delight of affection and the desire of knowing the things which were of thought, and that he followed obediently the things which his spirit had dictated; wherefore he applied himself to the right ear.” After relating some intelligent conversation with him concerning analytical knowledge, and about the Lord, Swedenborg, continues,— “A woman appeared to me, who stretched out her hand, wishing to stroke his cheek; when I wondered at this, he said that when he was in the world such a woman often appeared to him, who as it were stroked his cheek, and that her hand was beautiful. The angelic spirits said that such women sometimes appeared to the ancients, and were called by them Pallades, and that she appeared to him from spirits who when they lived as men in ancient times, were delighted with ideas and indulged in thoughts, but without philosophy, and because such spirits were with him, and were delighted with him because he thought interiorly, they presented representatively such a woman.” (AC 4658)These things are said to illustrate the quality of men who relate to the inner ear, namely, that they have an interior perception of truth as if it were told to them; and that they speak and write it obediently, delighting in it, and perceiving that it is true because it agrees with their interior life. In the Greatest Man they are in the outer ear who love to receive by hearing and impart what they receive without discrimination of quality, though as they are a part of heaven, they must have greater general delight in receiving and faithfully repeating good things. The drum of the ear loves to collect in a summary, in which all particulars are fairly and fully presented, all that comes from the outer reporters. The bones love to draw from that summary whatever coheres in a sequence, and with an inflexible stiffness to prevent anything from passing which will not make part of a receivable sequence. The vestibule loves to perceive and to transmit to the brain and to the whole heaven its impressions of the power and quantity of the truth received. As organs of equilibration, the correspondence of the semi-circular canals is perhaps indicated by the common expression "to keep a level head,” that is, to keep a clear sense of our position and relation to circumstances, and of what is to be done. If they have any part in the hearing, as suggested, it is likely to be a part relating definitely to what is to be done, and this, perhaps, is the discernment of articulation. And the cochlea loves to know the inner wisdom and purpose of the instruction, in its effect upon the harmony of the heavens and their openness to receive interior life from the Lord, which effects conjunction with Him. All the desire of the heavens for these things is concentrated in the ears; and the ears, in turn, transmit to the desiring angels the instruction they receive, with their own love for it, and desire to obey it. As to whence come the sounds to the angels of the ears, we have no instruction. But they may come in part from spirits and men outside of the heavens; for we read that the thoughts of these from affection are heard in heaven: — “The supplication, although tacit, of those who supplicate from the heart, is heard as a cry in heaven. This is the case when men only think, and more when they bemoan themselves, from a sincere heart. ... It is the same with those who mourn; (dolent for docent) they are heard in heaven as crying. Not only the thoughts, but more especially the affections, which are of good and truth, speak in heaven.... Affections for evil and falsity are not at all heard in heaven, even if the man who supplicates from them cries aloud with his hands tightly closed, and raises them and his eyes to heaven. These are heard in hell, and there also as “cries if they are ardent.” (AC 9202, see also SE 4821)Affections and prayers that are only individual, we should suppose would be heard only by individuals or small societies; but those that express general states of the community might be heard by larger bodies. Also those in the province of the ears may be affected by the speech of those in the provinces of the lungs and the mouth, who utter the Word of the Lord and thoughts of Divine wisdom from it. To the inner ear, besides the interior wisdom received from this source, may there not come also interior perceptions of wisdom from the Lord Himself, as we now receive them from spirits and angels? |