306 



VOICE AND SPEECH 



The essential difference between the production of notes in the lower 

 register, or chest voice, and in the higher register, or falsetto, has been 

 much debated. The lowest notes which can be uttered by any given 

 voice are chest notes, the highest are falsetto notes ; but there is a de- 

 batable land common to both registers, and medium notes can be sung 

 either from the chest or from the head. Chest notes impart a vibration 

 or fremitus to the thoracic walls, from the resonance of the lower air- 

 chambers, the trachea and bronchi; and this can be distinctly felt by 

 the hand. In head notes or falsetto the resonance is chiefly in the 

 upper cavities, the pharynx, mouth, and nose. As to the mechanical 

 conditions in the larynx, there is a pretty general agreement that during 

 the production of falsetto notes the vocal cords are less closely approxi- 

 mated than in the sounding of chest notes. The escape of air is conse- 

 quently more rapid in the head voice, and a falsetto note cannot be 

 maintained so long as a note sung from the chest. But it is only the 

 anterior part of the rima glottidis that is wider in the falsetto voice ; 

 the whole of the glottis respiratoria, and even the posterior portion of 

 the glottis vocalis, are closed during the emission of falsetto notes. 



Fig. 144. Position of the 

 Glottis preliminary to the 

 Utterance of Sound, rs, false 

 vocal cord; ri, true vocal 

 cord; ar, arytenoid cartilage; 

 b, pad of the epiglottis. 



Fig. 145. Position of Open Glottis. 

 /, tongue; e, epiglottis; ae, ary- 

 epiglottidean fold; c, cartilage of 

 Wrisberg; ar, arytenoid cartilage; 

 o, glottis; v, ventricle of Mor- 

 gagni; ti, true vocal cord; ts, false 

 vocal cord. 



Oertel has stated, and the statement has been confirmed by others, 

 that the free edge of the vocal cord alone vibrates in the falsetto voice, 

 one or more nodes or motionless lines parallel to the edge being formed 

 by the contraction of the internal part of the thyro-arytenoid muscle, 

 which thus acts like a stop upon the cord. 



Approximation of the vocal cords may take place in certain 

 acts unconnected with the production of voice. Thus, a cough, as 

 has already been mentioned, is initiated by closure of the glottis. 

 During a strong muscular effort, too, the chink of the glottis is 

 obliterated, and respiration and phonation both arrested. The 

 object of this is to fix the thorax, and so afford points of support 

 for the action of the muscles of the limbs and abdomen. But con- 

 siderable efforts can be made even by persons with a tracheal fistula. 



Speech. Ordinary speech is articulated voice voice shaped and 

 fashioned by the resonance of the upper air-cavities, and jointed 



