6 1 8. VOICE AND SPEECH. 



The strength of the voice depends partly on the degree 

 to which the vocal cords can be made to vibrate ; and 

 partly on the fitness for resonance of the membranes 

 and cartilages of the larynx, of the parieties of the thorax, 

 lungs, and cavities of the mouth, nostrils, and communi- 

 cating sinuses. It is diminished by anything which 

 interferes with such capability of vibration. The intensity 

 or loudness of a given note with maintenance of the same 

 " pitch," cannot be rendered greater by merely increasing 

 the force of the current of air through the glottis ; for 

 increase of the force of the current of air, cceteris paribus, 

 raises the pitch both of the natural and the falsetto notes. 

 Yet, since a singer possesses the power of increasing the 

 loudness of a note from the faintest "piano" to "fortis- 

 simo " without its pitch being altered, there must be some 

 means of compensating the tendency of the vocal cords 

 to emit a higher note when the force of the current of air 

 is increased. This means evidently consists in modifying 

 the tension of the vocal cords. When a note is rendered 

 louder and more intense, the vocal cords must be relaxed 

 by remission of the muscular action, in proportion as the 

 force of the current of the breath through the glottis is 

 increased. When a note is rendered fainter, the reverse of 

 this must occur. 



The arches of the palate and the uvula become contracted 

 during the formation of the higher notes ; but their con- 

 traction is the same for a note of given height, whether it 

 be falsetto or not ; and in either case the arches of the 

 palate may be touched with the finger, without the note 

 being altered. Their action, therefore, in the production 

 of the higher notes seems to be merely the result of involun- 

 tary associate nervous action, excited by the voluntarily 

 increased exertion of the muscles of the larynx. If the pala- 

 tine arches contribute at all to the production of the higher 

 notes of the natural voice and the falsetto, it can only be by 

 their increased tension strengthening the resonance. 



