556 THE HUMAN BODY 



and another, ', the hard breathing, answering somewhat to our h 

 and indicating that the larynx was to be held open, so as to give 

 a friction sound, but not voice. 



In whispering there is no true voice; the latter implies true 

 tones, and these are only produced by periodic vibrations ; whisper- 

 ing is a noise. To produce it the glottis is considerably narrowed 

 but the cords are not so stretched as to produce a sharply defined 

 edge on them, and the air driven past is then thrown into irregular 

 vibrations. Such vibrations as coincide in period with the air 

 in the mouth and throat are always present in sufficient number 

 to characterize the vowels; and the consonants are produced in 

 the ordinary way, though the distinction between such letters as 

 P and B, F and V, remains imperfect. 



