HARMONY AND DISCORD. 201 power it has to impart additional pleasure. The howling or moaning of the wind has sometimes this character, and produces a deep impression upon all minds sensitive to sound. The dying away of sound is especially noted as touching: 'that music hath a dying fall.' It may be, that a muscular feeling enters into this sensation: the gradually increased or relaxed tension of the muscles of the ear being a probable accompaniment of the increase or diminution of loudness. We cannot affirm, however, that it may not be due to the auditory nerves alone. When the pitch is gradually changed, as well as the degree, we have a farther modification introduced into musical composition, but apt to degenerate into the 'whine' or 'sing-song.' In the notes of birds, we may trace this effect; in the execution of accomplished singers, in the violin and other instruments, and in the cadences of a musical orator, we may likewise observe it; in all cases telling powerfully. 10. Harmony and Discord.-The concurrence of two or more sounds may be pleasing or unpleasing, irrespective of their character individually. The pleasurable concurrence is called Harmony. It is dependant upon the numerical relationship of the vibrations of the two sounds. Simple ratios, as 1 to 2 (octave), 2 to 3 (fifth), 3 to 4 (fourth), 4 to 5 (major third), 5 to 6 (minor third), are harmonious in the order stated. All these are admissible in musical composition, and are termed chords. The combination 8 to 9 (a single tone) is a dissonant combination; 15 to 16 (a semi-tone) is a grating discord. It has already been mentioned that an individual sound whose character is sweetness, is already a harmony, or concord of many sounds; the main tone being combined with overtones. In music, these sounds are still farther combined, according to the general laws of harmony. The pleasure of harmony is a wide-spread fact of the human mind; it extends to sight as well as to hearing, and is not wanting in the inferior senses; we may have harmonizing or discordant tastes. In the higher emotions, a concurrence may be either harmonious or discordant. The foundation of the pleasure is probably the same throughout; it is a general principle whereby mental states are regarded as either cooperating, or conflicting, with each other; in the one case, economizing nervous power and bringing pleasure; in the other, wasting power and causing pain. 11. Timbre. This means the difference between sounds, otherwise, the same, proceeding from different materials, instruments, or voices. We recognize a qualitative difference between the flute and the violin, or between the trumpet and the clarionet; we can distinguish between one violin and another, and between different voices sounding the same notes with the same intensity. These differences are now explained by the presence of auxiliary upper tones in all instruments; which tones vary with the material and the instrument. It is supposed that perfectly pure tones identical as regards pitch and intensity, would be undistinguishable, whatever might be their source. 12. Articulate sounds.-Of articulate sounds, some have a character so peculiar that our discrimination of them is no surprise. The hissing sound of s, the burring of the r, the hum of the m, are well marked modes of producing variety of effect. We can understand how each should impart a different kind of shock to the nerve of hearing. So we can see a reason for distinguishing the abrupt sounds p, t, k from the continuous or vocal sounds b, d, and g, and from the same sounds with the nasal accompaniment m, n, ng. quite so easy to explain the distinction of shock between the labials, dentals, and gutturals; still, if we compare p (labial), with (guttural), we can suppose that the stroke that gives the k is harder than the other. The vowel sounds are explained by the over-tones (octaves) concurring with each fundamental tone, and varying according to the resonance of the mouth, the form of which is altered for each vowel. When the ground tone is heard nearly alone, the sound has the character of u (full). The o has, along with the ground tone, the next octave audibly combined. The a ARTICULATE SOUNDS. 203 (ah) is characterized by the marked presence of the very high. octaves.* The same principle is applied to explain differences in the consonant sounds; but as respects these, there are other palpable distinctions such as we have alluded to above. Some persons are distinguished by their nice discrimination of articulate sounds. If the foregoing theory be correct, a good ear for musical notes should be also a good ear for articulation, seeing that the articulate sounds involve composite musical tones. An ear for pitch is thus the basis both of music and of speech. Strictly speaking, however, this applies to the vowels. The discrimination of consonants may depend on other qualities of the ear; a circumstance requiring to be adverted to, seeing that, in point of fact, the good musical ear is not always a good articulate ear. The sense of Time is not confined to any organ or any class of feelings; but it may attain to great perfection in hearing. 13. The perception of distance can result from nothing but experience. I quote from Longet. As soon as the organ presents a sensibility and a development sufficient for discerning easily the relative intensity of two consecutive sounds, nothing farther is necessary in order to acquire the notions of distance and direction of the body from which the sonorous waves emanate. In fact, if a sound is already known to us, as in the case of the human voice, or an instrument, we judge of its distance by the feebleness of its impression upon the nerve of hearing; if the sound is one whose The following is Helmholtz's table for the leading vowel sounds:— GroundVowel. Tone. 2nd. 3rd. 4th. 5th. 6th. 7th. a (ah) strong (weak) weak middling stronger stronger stronger than 3 and 4. The parentheses denote that the tones they inclose are not absolutely neces sary to the making of the special vowel-sound. intensity, at a given distance, is unknown, as, for example, thunder, we suppose it nearer according as it is louder.' We are apt to mix inferential processes with our judgment of distance. If we are led to imagine that a sound is farther off than it really is, we seem to hear it stronger than it is. Awaking suddenly in the night, we hear a faint noise, and suppose it much louder, our notion of its real distance being for a few moments vague and confused. It being an effect of distance that sounds fade away into a feeble hum, when we encounter a sound whose natural quality is feeble, like the humming of the bee, we are ready to imagine it more distant than the reality. 14. Direction. This is a purely intellectual sensation, in other words, is of importance as leading us to perceive the situation of the objects of the outer world whence the sound takes its rise. The following extract from Longet indicates the kind of experience that gives us the feeling of direction : 'With regard to the direction of the sonorous waves, we can at present only say, that the knowledge of it is owing to a process of reasoning applied to the sensation. Thus, we hear distinctly a sound emanating from a given point, whatever be the position of the head; but the ear being able to judge of slight differences in the intensity of sounds, we remark that, in certain positions of the head, the sound seems stronger. We are hence led to place our head in one fixed position as regards the sounding body. But our sight tells what is this direction of most perfect hearing; and we then apply the observation made on bodies that we can see to those that are not seen.' The combined action of the two ears also favours the perception of direction of sound very materially. A person that has become deaf on one ear, is usually unable to say whether a sound is before or behind. The change of effect produced by a slight rotation of the head, is such as to indicate direction to the mind. For while the sound becomes more perceptible on one ear,-the ear turned to face the DIRECTION OF SOUNDS. 205 object more directly,-the sound in the other ear is to the same degree obscured. When the head is so placed, after various trials, that the greatest force of sensation is felt on the right ear, and the least on the left, we then infer that the sounding body is away to the right; when the two effects are equal, and when any movement of the head makes them unequal, we judge the sound to be either right in front or behind; and we can further discriminate so as to determine between these two suppositions.* The sense of direction is by no means very delicate, even after being educated to the full. We can readily judge whether a voice be before or behind, right or left, up or down; but if we were to stand opposite to a row of persons, at a distance, say, of ten feet, we should not be able, I apprehend, to say which one emitted a sound. This confusion is well known to schoolmasters. So it is next to impossible to find out a skylark in the air from the sound of its song. 15. The duration of the feeling of an individual beat can be appreciated by noting at what intervals a succession of beats seems an uninterrupted stream of sound. This makes, in fact, the inferior limit of the audibility of sounds. From the experiments of Helmholtz, it would appear that a series of beats begins to be felt as continuous when they number * According to Ed. Weber, in determining the direction of sounds, we employ the external ear for those coming from above, below, behind, before; the tympanum for those coming from left to right. He made the following experiments:-The head was inserted in water, the air-passage being filled with air, so that the tympanum was free to vibrate. In that case, the ear recognized the sounds as external to itself, but could distinguish them only as right or left in direction. When, farther, the ear itself was filled with water, and the free action of the tympanum arrested, the sense of externality altogether was lost. The feelings were regarded as subjective. It was observed by E. H. Weber that the uniting of the double sensation from the two ears (analogous to binocular vision) has its limits. If two watches with different rates of ticking are held before one ear, the ear distinguishes the periods when the strokes of the two fall together, and forms to itself a rhythm out of the two series of strokes. If the watches are applied, one to each ear, the sense of rhythm is lost. The mind can no longer make the combination effected when the two watches are applied separately to the two ears. |