554 VOICE AND SPEECH 



produced outside the larynx. Thus, we obtain vowels or sonants 

 and consonants. The former are dependent upon the vibrating quali- 

 ties of the vocal cords and are, therefore, musical sounds, while the 

 latter are noises caused by irregular oscillations of the mouth parts. 

 One of these extralaryngeal constrictions, against which the ex- 

 piratory current of air is forced, is formed by the hps, another by 

 the teeth and the tongue and still another, by the soft palate and the 

 tongue. 



While the fundamental character of the vowels is determined by the 

 vibration of the vocal cords, a special quahty is imparted to them by 

 the varied resonance of the oral cavity. Such factors as the size and 

 shape of this cavity, the position of the tongue and the shape of the 

 soft palate play a part in their formation. Their influence is chiefly 

 directed toward the reinforcement of certain overtones. This 

 view which is essentially the one advocated by Helmholtz,^ has been 

 modified somewhat by Hermann, ^ who claims that the mouth does not 

 act as a mere resonator, but actually gives rise to secondary musical 

 notes which need not be harmonics of the laryngeal sound. 



As has just been stated, the consonants are produced by the various 

 constrictor adjustments of the mouth-parts, i.e.j by ^' positions of articu- 

 lation. " In accordance with the seat of the obstruction, these sounds 

 are classified as labials, dentals, gutturals and nasals. Every one of 

 them may be characterized as soft and hard, the former designation 

 being appHed to them if they are formed during phonation and the 

 latter if the vocal cords do not take part in their production. The 

 sound D, for example, is a soft dental sound, because the simultaneous 

 vibration of the vocal cords gives it quality, while the sound T is hard, 

 because it is a pure dental sound and is not accompanied by phonation. 

 Griitzner has divided the consonants into semivowels, explosive and 

 friction sounds. Among the first may be mentioned the sounds m, n, 

 ng, I and r. Thus, if sounded in part through the nose, as "reso- 

 nants, " as in him, hen, or being, they assume the character of vowels, 

 because they are produced by the vibration of the vocal cords, while 

 the air is forced out largely through the nasal cavity imparting to them 

 a peculiar nasal resonance. But if employed as real consonants, as 

 in make or no, they acquire the characteristics of explosive sounds. 

 Typical explosives are the sounds p and v (labials), t and d (linguo- 

 palatals or dentals) and k and g (gutturals). They are said to be 

 formed with or without voice, because the production of some of them 

 necessitates a vibration of the cords, for example, the sounds b, d and 

 g. Friction sounds or frictionals, are produced by the passage of the 

 expiratory air across the edges of constricted areas, which are thereby 

 thrown into vibration. In this way, there are produced at the labio- 

 dental communication the sounds of/, v, and w; the first of which does. 



1 Lehre von den Tonempfindungen, Braunschweig, 1877. 



2 pfliiger's Archiv, xlvii, 1890, 44. 



