Voice

VOICE, a general concept uniting sounds originating from the human larynx, regardless of whether they are intended to express thought and feeling or are the result of unconscious reflex muscle movements. In the development of V., three stages should be distinguished, in which the quality of these sounds is not equivalent. In the first stage, in the newborn, V. is an innate motor reflex connected with internal and external irritations. This reflex is inherited and is expressed by such homogeneous sounds that even the mother usually cannot distinguish her child by V. This V. sharply differs from human conscious speech (2nd stage), which is already a neuropsychological act. Although speech also belongs to the category of reflexes, still, in contrast to the unarticulated cry of a child, it suggests the presence of experience and imitation. Here individual properties of V. manifest not only in a given personality but may be characteristic of an entire nation or people. If there are no external obstacles from the psyche, hearing, and voice-forming organs, all people can master speech. In the third, highest stage of development, the vocal apparatus is brought into a special state, which gives the right to consider it as a musical instrument. The V. of an artist, especially a singer, is developed through long and persistent work, the success of which depends on natural aptitude and musical talent. The study of the problem of voice formation encounters great difficulties, as it requires familiarity with a whole series of sciences. Anatomy, physiology, and physics are necessary, as here we are dealing with the study of respiratory movements, the origin of sound in the larynx, and articulation; psychology introduces the sphere of processes of sound perception, linguistics and philology acquaint with the extensive field of studying the languages of different peoples, finally otorhinolaryngology is needed when encountering pathological processes in voice formation. That area of knowledge which aims to study the conditions of voice formation in the normal organism, its timbre, pitch, strength, and duration, is called experimental phonetics; its task is to study facts and draw conclusions from the data obtained, for which it uses observation of phenomena occurring under natural conditions and under conditions of a specially set experiment. In phonetics, one cannot always rely on the accuracy of registering phenomena by our senses, and therefore in such cases recourse is had to the help of various instruments and devices that objectively testify to the observed facts. The founders of modern scientific experimental phonetics are considered to be the French abbot Rousselot and Rosapelli, who in the late 19th century introduced recording devices into use. Then thanks to the works of Gutzmann and his school, phonetics received further development and moved forward significantly. But interest in the study of voice formation is noted since the time of Hippocrates, Galen, da Vinci, and others. These aspirations often led to important discoveries. Thus, Garcia (1857), not being a physician, introduced the laryngoscopic mirror into use. Physiologists and physicists, such as Brücke and Helmholtz, clarified the role of the resonant tube and larynx in the formation of V. To understand the mechanism of voice formation, the vocal apparatus is compared with musical instruments, in which the driving force for producing sound is blown air—flutes and reed pipes. In the flute, each sound requires a certain length of pipe with an unchanged mechanism at its place of formation, while in the reed pipe, on the contrary, each tone corresponds to a certain size of the reed, while the length of the pipe has only a minor influence on the pitch of the sound. But the vocal apparatus can produce sounds of different pitch due to the fact that the vocal cords, which are considered as a double reed, have the property of changing their size, shape, tension, and elasticity, while the resonant tube—the pharynx, mouth, and nasal cavity—remains unchanged in length. The mouth, however, following a volitional impulse, can change its shape and volume and thereby give the sound special shades. To produce a voice sound, it is necessary for air pressure to be exerted on the vocal cords from the side of the trachea and bronchi, which is achieved by a very complex system of respiratory muscles. Breathing during speech and singing differs from quiet breathing. At rest it occurs automatically and externally manifests in the movement of the walls of the chest and abdomen, which rise and fall evenly during inspiration and expiration. These respiratory movements are influenced not only by the medulla oblongata but are connected in the cerebral cortex with numerous cortical respiratory centers, as a result of which they can change with different emotional states. The duration of inspiration is approximately equal to expiration. During inspiration, the vocal cords are in a position intermediate between the strongest abduction and adduction, and the glottis has the shape of an isosceles triangle. During expiration, the glottis tends to narrow somewhat, which occurs automatically. During phonation, due to the closure of the glottis, air does not have free exit and is used to set the vocal cords into vibration; as a result, a whole series of changes occurs in the process of breathing. During singing and speech, it is more dependent on will. The relationship between inspiration and expiration changes sharply, as the expiration phase is noticeably lengthened. Depending on the phonetic purpose (counting, reading, singing, etc.), the number of inspirations can drop to 9-10 per minute. The flow of inspiration accelerates, and the range of movement increases. Observation shows that during speech and singing, a person inspires mainly through the mouth. Apparently this is of great importance for singers, as the rapid passage of air through the wide opening of the mouth facilitates the establishment of the required intrabronchial pressure in the subsequent phase of expiration, coinciding with phonation. In the literature there are indications that when inhaling through the nose, the diaphragm makes less energetic movements than when inhaling through the mouth. During voice formation, in the subglottic space and in the system of the trachea, bronchi, and alveoli, a certain air pressure is created, which can be maintained at different levels depending on the quality of the sound produced. The interaction between the vocal cords and intrabronchial pressure is regulated automatically due to an innate reflex. Pressure increases as the pitch rises, it changes when pronouncing individual vowels and with various shades of voice and its strength. If during quiet inspiration and expiration the pressure height is insignificant (according to Gutzmann, it fluctuates from 0.73 to 2.19 mm mercury), then during speech and singing the pressure rises sharply. According to Cagniard-Latour, during a loud cry it reaches 69.48 mm, during singing high tones—14.7 mm, medium tones—11.7 mm, during whispering—2.2 mm. Grützner showed that each vowel requires its own pressure: a—9.19, o—14.55, u—14.7, e—15.58, i—16.17 mm mercury. From this it follows that there is the closest relationship between pressure, vocal cords, and the resonant tube. A number of active forces participate in maintaining intrabronchial pressure at the required level. 1. In this respect, the smooth musculature of the trachea and bronchi plays a very significant role. At the moment of glottal closure, the bronchi, like other hollow organs, under the influence of increasing lateral pressure as a result of excitation, begin to narrow and thereby increase the pressure of air on the walls of the bronchial tree. As soon as this pressure drops when the glottis opens, the endings of the vagus nerve cease to be excited, and a period of bronchial dilation begins under the influence of the respiratory center, which is also facilitated by the suction action of the diaphragm during inspiration. The smooth musculature is embedded in the mucous membrane of the bronchi over a wide area up to the alveolar passages, and this ensures the uniformity and constancy of its action. Schilling showed that in the system of the trachea and bronchi during phonation, pressure begins to rise before the abdominal and chest muscles contract. Some attribute the decrease in the intensity of V. to the dilation of the membranous part of the trachea, which can occur during a strong cry, as well as on the basis of acute and chronic diseases or senile changes. On the contrary, the resonant V. of small children is associated with the comparative power of their smooth musculature. 2. The second moment, which can influence the degree of intrabronchial pressure, comes down to the activity of the diaphragm. Being the boundary between the abdominal and thoracic cavities, during phonation it is subjected to the action of abdominal pressure and intrathoracic pressure. Due to the fact that the diaphragm muscles during this process are in a state of some tone, it can have a balancing value between these two forces. The degree of participation of the diaphragm during inspiration and phonation can be greater and lesser; thus, during strong, deep inspiration, the chest muscles participate more energetically than the diaphragm, and its functional significance is weakened.

The question of diaphragm tone has been little studied, yet it is of great importance in voice production, especially for singers, for whom maintaining a certain degree of diaphragm tension while holding a tone serves as a sign of good vocal technique. In different individuals, the degree of diaphragm tension varies; it is less in persons with narrow and long chests than in those with broad chests.-3. The third factor affecting intrathoracic pressure is the force that develops during the passive or active collapse of the chest walls. The more the chest cavity expanded during inhalation, the greater the potential for developing this force during subsequent phonation. The degree of elevation and depression of the chest walls varies among different individuals during speech and singing when performing the same task; there is even a whole series of persons in whom the chest remains immobile throughout the entire time of tone holding, while the voice strength can be brought to maximum.-4. The fourth factor is the strength of the abdominal press, which can adapt to volitional impulses and be in close relationship with the motor function of the vocal cords and the resonator tube, as well as with the respiratory muscles. The combined action of the abdominal press muscles can be very strong, but it is weakened and regulated by the tension of the diaphragm. In the same direction to soften the rough jolts from the abdominal press, the soft and elastic internal organs act, especially those that contain air. The combined work of all the mentioned forces, performed by smooth and striated musculature, is carried out automatically. With mutual support, it is able to maintain the necessary intrabronchial pressure at a certain height for a longer or shorter time. With average voice strength, an adult can hold a tone for 25-30 seconds, while some singers extend the duration to a minute or more (Patti). The amount of air expended in speech and singing is about 1,500-2,400 cubic cm, i.e. 3-4 times more than at rest (Nadoleczny); however, in some singers it does not exceed 500-600 cubic cm per breath. The external movements of the chest and abdominal walls during sound production are expressed in the chest and abdomen expanding or contracting, similar to what is observed during quiet breathing. The study of these movements by simple inspection and palpation does not give precise results; therefore, recourse is had to graphic recording of them on smoked kymograph paper, for which three belts of Gutzman's pneumograph are used, which are placed on the chest, at the level of the nipples and the upper part of the epigastrium, and on the abdomen, at the level of the navel. The movements are transmitted to Marey's capsule with a recording pen and appear in the form of a curve - a sinusoid, the ascending limb of which corresponds to inhalation, and the descending one to exhalation. At rest, the recording curves show that the movements at all levels occur in parallel and synchronously, and the inhalation curve is slightly shorter than the exhalation curve. In speech and singing, in addition to the fact that the curves corresponding to exhalation are lengthened, they can take different directions and become non-parallel; while some of them descend, others have an ascending or horizontal direction. The curve relating to the middle belt expresses the total movement, since the pneumatic belt at this level comes into contact with the ribs of the lower part of the chest and the soft walls of the epigastrium, the movements of which can be opposite.-The movements of the diaphragm were studied by means of X-rays. Shilling set up an orthodiaphragmograph and established, '31 voice that only 20% of the inhaled air is accounted for by the activity of the diaphragm. There are almost no studies on breathing during free speech, as it is difficult to find homogeneous conditions for such observations. Many have sought to unravel the mystery of the singing voice by studying the types of respiratory movements when performing the same tasks. To this day, no unanimous conclusions have been reached, as the evaluation of a singer's voice was based on individual subjective sensations, while objective data on respiratory movements differed greatly and were interpreted differently. Undoubtedly, with a change in the type of external respiratory movements, the mechanism for maintaining intrabronchial pressure changes, and the volume of inhaled air also changes. It should be noted that the type of these movements also affects the height of the general blood pressure. In forced singing and when holding high tones, it rises to a significantly greater height if intrabronchial pressure is maintained by the collapsing chest walls. Such singing is often accompanied by stagnant phenomena: the face flushes, the veins of the neck swell. The sound of the voice arises in the larynx between the closed vocal cords, on which pressure is exerted by the air from the trachea. When the air squeezed from the lungs meets an obstacle in the closed glottis, the pressure in the trachea increases; as soon as it reaches a tension exceeding the force of closure of the cords, part of the air breaks through the glottis due to the divergence of the cords, but they come together again to repeat the same thing. These explosive air bursts occur more frequently the higher the sound produced. In a continuous series of rapid successive compressions and rarefactions of air, a sound longitudinal wave is formed, which, thus, having originated in the larynx, propagates in space in all directions at a speed of 343 meters per second. Stroboscopic studies have shown that the vocal cords perform the same oscillations as the edges of the lips when playing brass instruments. The sound formed in the larynx and not yet modified in the resonator tube is called primary in phonetics. The closure of the vocal cords during phonation occurs under the influence of a series of laryngeal muscles: the lateral arytenoid-cricoid muscles bring the cords together and narrow the membranous part of the glottis, the anterior cricothyroid muscles stretch the cords between their points of attachment and give the height of the voice, the internal thyroarytenoid muscles, lying in the thickness of the cords, differ from others in that they consist of fibers arranged in different directions, whereby the vocal cords can change their length, width and thickness and thus influence not only the height but also the timbre of the voice. Apparently the characteristic features of male, female and children's voices are connected with the structure of these muscles. The mentioned muscles participate in the closure of only the anterior part of the glottis, while the posterior, respiratory part, closes by the action of the transverse and oblique muscles. If the bases of the arytenoid cartilages do not come together closely during phonation, an opening remains between them, through which air from the trachea can escape in the form of a jet. Such leakage constantly occurs in voice production in all mammals, since on the inner surfaces of the arytenoids there are notches (hiatus intervocalis). In voice production, the transition of the glottis from the respiratory to the phonatory position can occur with different speed and energy, in connection with which a solid, soft and aspirated attack of the sound is distinguished; the latter occurs, for example, in pronouncing the German h. The role of the epiglottis in phonation is unclear; according to some observations, it rises in high tones and falls in low tones, but there are also reverse relationships; when pronouncing a vowel it is thrown forward more than with other vowels. In conversational speech, the height of the voice is kept within the limits of the chest register, which requires the least tension of the vocal cords - in men from a to c, in women and children an octave higher. Due to the abundance of overtones and the change of tone heights in the voice during speech, it is often difficult to determine the actual height of the voice in speech. In singing, the voice serves musical purposes, and therefore the range of tones is significantly wider and the duration of holding them is longer. Voices are divided into 6 typical groups: 3 female (soprano, mezzo-soprano and contralto) and 3 male (tenor, baritone and bass); in addition, there are distinctions (depending on musical properties) between dramatic, lyric and light tenors, high and low baritones, high, low and octave basses, and in children - treble and alto. Soprano can be dramatic, lyric and coloratura; mezzo-sopranos approach either contralto or dramatic soprano. According to Stockhaus, the voice extends (the numbers show the number of vibrations per second): In Basses.........from

h (258,6) » e³ (1303,4) Phenomenal voices spanning three or more octaves have been described. In singing voice, in connection with the sensation of its resonance, chest, head, or middle registers and falsetto are distinguished. In chest voice, the vocal cords are brought together along their entire length and vibrate in their full width; the slit between them appears in the form of a narrow straight line; as the pitch rises, the cords shorten, and the slit takes on a slightly lancet-like shape. In the middle register, the characteristic tension of the inner thyroarytenoid muscle begins to weaken, and the height of the voice is maintained by the increasing activity of the anterior cricothyroid muscle. In falsetto, the edges of the vocal cords thin out, and the vocal slit remains slightly open, for which reason some think that more air is expended in falsetto; the voice Falsetto voice is not rich in overtones, sounds soft, and lacks strength. In practice, singers use the so-called 'covering' of the sound for as imperceptible a transition as possible from the chest register to the middle register: if, for example, the vowel a is sung with a strong voice in an ascending scale, then at a certain height the voice becomes piercingly shrill and openly resonant. By means of technical techniques, which consist mainly in the use of the diaphragm, the voice can obtain a sound with a brilliant, matte timbre (closed). This limit in the scale of the chest register is called the 'break' of the voice, which should not be confused with the break of the voice in youth (mutation). The difference in timbre between open and closed sounds is confirmed not only by hearing but also by sound analysis: in the former, the octave stands out more brightly among the overtones, in the latter—the fundamental tone and the 5th and 6th overtones. In whispering, the vocal cords come together in the membranous part, while in the respiratory part between the arytenoids the slit remains unclosed. The whispering noise is produced by the friction of air in the vocal slit. The pitch of whispered speech depends on the natural tone of the resonator tube and changes with each vowel. The voice becomes similar to a whisper in various deformities in the laryngeal cavity, in artificial larynx, and in its absence.-In ventriloquism, the formation of the voice occurs with the strong approximation of the true and false vocal cords with the simultaneous closure of the entrance to the larynx by the epiglottis,-The voice is heard from a distance. The physiological significance of Morgagni's ventricles for voice production has not been clarified. Most authors deny the role of the latter as a resonator. The entire body of the larynx does not remain inactive during voice production; although not within wide limits, the larynx can rise and fall, as well as shift to the sides. These movements depend on the strength of the intrabronchial pressure and on the activity of the external neck muscles and neighboring organs. The position of the larynx during singing varies due to the difference in the voice production mechanism in different individuals. The voice arising in the larynx is a complex sound, because in it one can distinguish the fundamental tone and a series of both harmonic and non-harmonic overtones, from which the nuances in the voice—its timbre—depend. In the resonator tube—in the pharynx, mouth, and nose—with hard and soft walls, some overtones are strengthened, others die down, so that the final individual color of the sound of the voice is formed upon its exit from the oral opening. The soft palate has a great influence on the fate of the sound coming from the larynx, which can separate the nasal cavity from the pharynx and mouth. If the soft palate is raised, the sound waves spread entirely through the mouth; when the palate is lowered to touch the root of the tongue, the sound acquires a nasal, nasal timbre; undoubtedly, in this case 'many overtones in the narrow passages of the nose are weakened and die down. Resonance of the voice in the nose is possible if an opening remains between the posterior wall of the pharynx and the soft palate. The accessory nasal cavities, due to their small size and the insignificance of the outlet opening, are not resonators. The question of the function of the soft palate in singing has not been finally resolved. Many researchers believe that resonance in the nose adversely affects the quality of the voice, even if it is weakly expressed; according to others, each vowel requires a certain degree of palate elevation during pronunciation. The color of the voice changes with the movement of the lips, cheeks, tongue, lower jaw, epiglottis, as well as with the lowering and raising of the larynx. The existing view that the chest cavity also serves as a resonator for the voice is currently refuted due to the constant variability of the lumen of the trachea and bronchi. Thanks to articulation, humans have developed the ability to articulate speech. Its elements—phonemes—are vowels and consonants. Each speech sound corresponds to a specific articulation and shape of the resonator tube. The main vowels a, e, i, o, u can have different shades. For the vowel a, the lips are widely open, the tongue lies at the bottom of the mouth, there is a large space between the soft palate and the root of the tongue, the larynx is almost as in rest; the epiglottis is slightly thrown back. For e, the lip opening is narrowed more and somewhat stretched towards the corners of the mouth. The tongue is raised in its middle part towards the middle of the hard palate, the tip of the tongue rests against the lower teeth, the larynx is raised. The epiglottis has moved forward. For i, the mouth is even more narrowed, the middle of the tongue almost touches the hard palate. The soft palate is strongly raised upward, the epiglottis has moved far forward, the entrance to the larynx is widely open. For o, the oral opening takes an oval shape, the lips are slightly elongated, the tip of the tongue is slightly raised and touches the gums. The larynx is slightly lowered. For u, the lips are strongly elongated forward, the oral opening is round but narrower than for o. The tongue forms a depression in the posterior parts, the larynx stands lower than for the other vowels. The oral cavity enhances those overtones that give the corresponding sound impression. With the help of resonators, it has been proven that each vowel is characterized by a specific formant, i.e., the oral cavity enhances for a given vowel one or more tones, the height of which does not depend on the height of the sound produced by the vocal cords. Thus, according to Helmholtz, a has its own tone-si², o-si³, u-f², i-f⁴ and d¹, e-f³ and si³. A vowel sounds brighter and more perfect if its formant coincides with the fundamental tone. This explains why singers replace one vowel with others at certain boundaries of the vocal range. Helmholtz's resonance theory of the voice, to the present day, despite many attempts, has not been refuted by anyone; it is usually contrasted with Hermann's theory, according to which independent sounds—formants—arise in the oral cavity, which are not among the overtones of the produced sound. Analysis by means of recording devices (oscillograph) has shown that each vowel corresponds to a specific curve, indicating the complex movements of air particles for individual vowels. The nature of vowels is further elucidated by Helmholtz's classic experiment with artificial reproduction of them through the voice 63 by the addition of many tones: in his apparatus, he made tuning forks tuned to specific tones sound and obtained all vowels, except for i, which is characterized by very high additional tones. Consonants are formed because a sudden obstacle is placed in the path of the sound wave moving from the larynx in the resonator tube. At the moment of stopping in its forward movement, the parts of the wave rush against each other, at which point its acoustic structure is lost, and the resulting noise is perceived as a consonant. Since every sound produced by a person always has a vowel color, the relationship between vowels and consonants is evident. Consonants differ from each other in the manner and place of formation. If complete closure occurs in the resonator tube at the moment of pronunciation, a noise from the burst is obtained—plosive consonants (b, p, d, t, k, g). With incomplete closure, fricatives, or spirants (f, v, s, sh, z, zh) are formed. M and n (nasals) correspond to the closure for b and d. For l, the change in the resonator tube occurs due to vibratory movements of the tongue and walls of the mouth; the sound wave does not undergo major disturbances in its structure. Therefore, they are called sonorous, or sonants, or semivowels; in some peoples (Japanese, some African tribes) there is no sound difference between l. ts, shch—complex diphthongs, are formed according to the type of plosives and fricatives. By the place of origin of consonants, three areas of articulation are distinguished: at the level of the velum curtain and the base of the tongue (palatals), at the level of the arch formed by the teeth of the upper jaw, the anterior part of the palatal vault, and the tip of the tongue (linguals), at the level of the lip opening (labials). This division facilitates the classification of consonants; in reality, all intermediate spaces between these points can be places of consonant formation, hence—their different shades in different people and peoples. Depending on the peculiarities and active participation of the places of formation, consonants can be hard (t, p, k) and soft (b, d, g). The composition of the noises of consonants includes both high and low overtones; in connection with this, they have different degrees of audibility. Thus, the consonant s can be distinguished from a greater distance than p or d. The clarity of speech is determined by the presence in the voice of very high, but weak in strength tones (over 3,000 vibrations per sec.).

Fletcher (1923), studying the intelligibility of speech with the help of electrical filters, showed that the number of words correctly understood over the telephone in relation to the total number decreases by only 5%, 'if one excludes overtones up to 500 vibrations per second. Excluding frequencies up to 1,000 vibrations absorbs 82% of the energy of speech and reduces intelligibility by only 15%; while absorption of frequencies above 1,000 vibrations per second leads to a sharp decrease (by 40%) in intelligibility, with the timbre acquiring a dull and dark character, whereas when low tones are absent, it becomes cutting with a metallic tint. It has been noted that when vowels are pronounced clearly, consonants are also heard more distinctly.'-In Voice, changes occur in connection with age. Under the influence of sex hormones during the period of sexual maturity, the larynx begins to grow in all its parts, and this leads to sharp changes in the pitch, strength, and timbre of the Voice. This phenomenon is called the breaking of the Voice or mutation. These changes are especially noticeable in boys, when a soprano or alto turns into a bass or tenor. Often during mutation, certain painful symptoms are observed in the form of hoarseness, huskiness, fatigue, unexplained coughing, and redness of the vocal cords. In girls, mutation proceeds less violently, and vocal changes are almost imperceptible. During the period of mutation, singing is not recommended for both sexes. In old age, due to the ossification of the larynx and atrophic processes in the muscles and glands, the Voice becomes weaker and often changes its timbre coloration, in women it often acquires a lower character. After castration and similar pathological processes during the period of maturity, the breaking of the Voice does not occur, and the child's Voice is preserved for life (the Voice of eunuchs). In addition to conversational speech, whispering, and singing, a number of varieties are noted in the voice. 1. The inspiratory voice is obtained by strong inhalation through not quite closed vocal cords and occurs during the cry of a newborn, during crying, etc. It is not strong and is limited to a few low tones,-resembling the Voice in ventriloquism. 2. The voice during laughter with the pronunciation of single sounds (ha, ha, etc.) occurs with a pitch of about 200-300 vibrations per second. 3. Cough is accompanied by a sound also with the participation of the vocal cords; a special sound shade occurs in barking cough, which depends on the subglottal swelling of the laryngeal walls. 4. The Voice, caused by the closure of the false vocal cords, is observed in pathological cases as compensation; it can also be developed artificially, for example, in simulation. 5. The speech of tracheotomized and laryngectomized persons occurs due to the air supply in the mouth, pharynx, esophagus, and even in the stomach. All automatic and conscious movements of the speech organs are united by a general psychic center, which covers a significant part of the periphery of the brain. For phonatory movements of the vocal cords and respiratory muscles, there is a special center in the front-outer part of the gyrus praecruciatus. From the cortical substance, volitional impulses go to the sensory center of Wernicke, and then to the center of Broca, where representations of the appropriate sounds are already formed.-The pathology of the voice can affect different parts of the vocal apparatus and lesions of the psychic centers of speech and hearing. A number of diseases of the larynx and improper function of the vocal cords lead to disorders of phonation. A large group of speech defects is associated with diseases of the articulatory and respiratory organs; these include stuttering, stammering, and related forms. golgi