SPEECH. 495 



cavity and aperture, that a resonator with a different individual 

 note is formed for each particular vowel. 



The sounds called consonants are caused by some check or im- 

 pediment being placed in the course of the blast of air issuing 

 from the air passages. They may be classified, according to the 

 part at which the obstruction occurs, as follows : 



1. Labials, when the narrowing takes place at the lips, as in 

 pronouncing b, p,f, v. 



2. Dentals, when the tongue causes the obstruction by being 

 pushed against the hard palate or the teeth, as in t, d, s, I. 



3. Gutturals, when the posterior part of the tongue moves to- 

 ward the soft palate or pharynx, as in saying k, g, gh, ch, r. 



Consonants may also be divided into different groups, accord- 

 ing to the kind of movements which give rise to them. 



1. Explosives are produced by the sudden removal of the ob- 

 struction, as with p, d, k. 



2. Aspirates are continuous sounds caused by the passage of a 

 current of air through a narrow opening, which may be at the 

 lips as in/, at the teeth as with s, or at the throat as in ch. 



3. Resonants are the sounds which require some resonance of 

 the vocal cords, and the air current is suddenly checked by clos- 

 ure of the lips as in m, or the dental aperture as in n or ng. 



4. Vibratory, of which r is the example, requires a peculiar 

 vibration of the vocal cords, while either the dental or the gut- 

 tural aperture is partially closed. 





