CXDULATORY FORCES. ACOUSTICS. 



[PITCH OF IIIE VOICB. 



considerable difference preMnted by the two sexes in the 

 walk of the larynx ; the male larynx being much more 

 expanded, and forming a mnch more acnte angle in 

 front. It ii not yet clearly understood what u the 

 oao*e of the different qualities of voice, as exhibited in 

 the tenor and baas, and the contralto and soprano. At 

 Mailer remarki " We mar form an idea of the oanse 

 of thene differences) of timbre, frm r.-collecting that 

 musical instrument*, made of different materials, as 

 metallic and gut-string*, metallic, wooden, and membra- 

 nous tongues, metallic, wooden, and paper pipes, or 

 flute*, may be tuned to the same note, but that each 

 will give it with a peculiar quality or timbre." 



In short, when the variations of the larynx in dif- 

 ferent individuals of both sexes, and at different ages, 

 under the rations circumstances more or less favourable 

 .o development of the respiratory organs, are con- 

 sidered, a* well as the remarkable fact that every human 

 being is characterised by a spooking voice peculiar to 

 himself, we shall be at no loss to understand why the 

 singing voice should vary in different persons, not only 

 in pitch, but also in quality. 



The voice termed falsetto has mnch engaged the 

 attention of physiologists. Most singers, particularly 

 males, besides their natural voice falling under one or 

 other of the before-mentioned characters, have the power 

 of producing a double series of notes, of a different de- 

 scription. To the second series of notes the name of 

 falsetto U applied. The notes of the natural voice 

 called also chest-notes are fuller, and distinctly in- 

 dicate a stronger vibration and resonance ; while the 

 falsetto voice has more of a humming character. It is 

 only with the natural voice that the deep notes can be 

 produced ; while the highest notes of a mole voice are 

 falsetto. The notes accompanying a middle pitch may 

 belong either to the natural or the falsetto voice. Thus 

 the two registers, as they are termed, of the voice are 

 not bounded in such a manner that the one ends where 

 the other begins, as, through a certain compass, they 

 run side by side. It is remarked that the bass voice 

 becomes falsetto lower in the scale than the tenor. In the 

 female voice there is less seldom presented a very marked 

 distinction between the natural and falsetto registers. 



In a human larynx, detached from the body, two dis- 

 tinct series of tones can be produced, when the tension 

 of the vocal cords is very slight. One of these series 

 corresponds to the tones of the ordinary voice, the other 

 to the tones of the falsetto voice. With a certain degree 

 of tension of the vocal cords, both these kinds of tones 

 may be produced sometimes the ono kind, sometimes 

 the other, being heard. With a different kind of tension 

 of the cords, notes of the falsetto character are con- 

 stantly produced, whether the current of air passing 

 through the glottis be forcible or feeble. If the vocal 

 ligaments bo much relaxed, the sounds of the ordinary 

 voice always result, whether tiie current bo feeble or 

 forcible. When a slight tension of the ligaments is 

 kept up, the falsetto w most easily produced by blowing 

 very gently ; while, if tho blowing be more energetic, the 

 sound belongs to the ordinary voice. Thus, two differ, n t 

 notes may be produced, under the same degree of ten.si.rn 

 of the ligaments, by a different force in the blowing ; 

 and tho distance of those two notes from each other may 

 be as much as on octave. " Tho real cause," says Miill. r, 

 "of tho difference between the falsetto and the notes of the 

 natural voice is, that, for tho former, the thin aperture 

 only of the lips of the glottis vibrates ; while, for the 

 latter, the whole breadth of the cords is thrown into 

 strong vibrations, which traverse a larger sphere." The 

 pecaliaritien of the voice in different individuals, must 

 be chiefly dependent on the particular form of their air- 

 p stages ana of the lining membrane*, and tho conse- 

 quent differences in their mode of resonance. That such 

 causes are adequate to produce all the varieties of the 

 voice 111 individuals, appears from the circumstance, that 

 many persons, by altering the form of their vocal organs, 

 can imitate tho various tones of the voices of other 

 individuals. 



The nasal quality of the voice U determined by like 



causes. This nasal tone appears to be given to the 

 voice in two ways: thus a nasal sound is produced, 

 though tho external openings of the nostrils be closed 

 when tho arches of the palate approach each other, and 

 the larynx ascends higher than in tho natural voice. 

 When tho nostrils are obstructed by mucus, a nasal 

 sound is produced; this obstruction having tho same 

 effect as the voluntary closure of the anterior opening of 

 the nostrils. In the second mode by which tho nasal 

 sound is produced, the nostrils arc open, the larynx 

 ascends considerably, the arches of the palate contract, 

 the upper surface of the tongue ascends towards tho 

 palate, so that the air passes between the narrowed 

 arches of the palate, and receives tho resonance of tho 

 nasal cavities without that of the cavity of tho mouth. 

 The deficiency of tone in the voice of old people, arises 

 from the ossification of the cartilages of tho larynx, and 

 the altered state of the vocal cords. It is unsteady, 

 owing to tho loss of nervous command over the nui^ 



The strength of the voice depends partly on the extent 

 to which tho vocal cords are capable of vibration, ami 

 partly on the great capacity of the chest, and the fitness 

 of the various parts, over which the air passes, for com- 

 municating resonance. The intensity or loudness of a 

 given note cannot be rendered greater by the mere 

 augmentation of the force of the current through tho 

 glottis. Such an increase of force in tho em: 

 will raise the pitch both of the natural and fa'. 

 notes. It is therefore concluded that the variation iu 

 the intensity of a note, without the alteration of its 

 pitch, must depend on some other cause than the mero 

 change in the force of tho current. Such a provision 

 plainly lies in the power of modifying the tension of the 

 vocal cords. To render a note more intense, without 

 increasing its pitch, the vocal cords must be relaxed in 

 proportion as the force of the current of the breath 

 through the glottis has increased. When it is desired 

 to render a note fainter, an opposite mode of action 

 must be adopted. 



The failure of perfectncss in the notes of the human 

 voice may arise from many causes. Variations in tho 

 temperature of the atmosphere, and in its states of 

 humidity, have a powerful influence on the pitch of tho 

 voice. During a cold, moist state of the atmosphere 



Erevalent in these islands, the voices of singers become 

 >wer by two or three notes ; while they regain their 

 usual pitch when the air becomes dry. Mr. Bishop 

 mentions, that when Grassini came to this country, 

 owing to the change of tho air from that of Italy, her 

 voice became one octavo lower. After singing for two 

 or tliree seasons, her natural voice returned, but it Lad 

 lost its attractions with the loss of tho low tones which 

 had gained her so great applause. After long singing, 

 dissonance of the voice is apt to arise ; this is easily 

 accounted for by the slight changes produced on thu 

 vocal cords in consequence of repeated tension, tog. 

 with tho fatigue of the muscles concerned, which, as in 

 other cases of muscular contraction, at length cease 

 accurately to obey the will, and hence afford unsteady 

 movements. 



tl'liiniliiig. Before leaving tho subject of tho human 

 voice, whistling deserves a few words. The sound in 

 whistling docs not arise from the vibrations of the lips. 

 Several experiments prove that tho lips are not throun 

 into vibrations. They may be touched, covered, or may 

 have a disc of cork with a central hole placed between 

 tli. 'in, and yet the same sounds will bo produced. It 

 has been supposed, then, that tho air is thrown into 

 sonorous vibration by friction against the borders of 

 the opening. According to Miiller, the cause of tho 

 vibration is the same friction of tho air; but tho vibra- 

 tion produced upon the borders of the op.-nin-, throws 

 tho whole column of air in the mouth into vibrations, 

 and tho vibrations of this column of air, by a reciprocal 

 influence, determine tho rapidity of tho vibrations of 

 I lie air at the orifice. The only difl'oreiice, according to 

 him, between whistling and the sounds of a pipe is, that 

 in whistling, the whole column of air is in constant pro- 

 gressive motion through tho tube and orifice ; while, in a 



