VOICE AND SPEECH 527 



or mouth. They are classified into labials, dentals, or gutturals, according 

 as the check takes place at the lips, between teeth and tongue, or between 

 back of tongue and soft palate. Each of these again can be divided into 

 soft and hard consonants as they are accompanied or not with phonation. 

 Thus when we pronounce D the production of the laryngeal sounds goes on 

 during the check of the sound produced at the teeth, whereas with T there 

 is an absolute interruption of phonation during the pronunciation of the 

 consonant. It is thus practically impossible to make any marked difference 

 between hard and soft consonants when whispering. 



In the production of nasal sounds such as NG the mechanism is the 

 same as for the production of B, D, G, except that the posterior opening 

 of the nares is not kept shut by the soft palate, so that part of the sound 

 comes continually through the nasal passages, when it acquires a peculiar 

 resonance. These sounds are on this account often spoken of as resonants.' 

 The aspirates are produced by the passage of a simple blast of air through 

 a narrow opening which may be at the throat as in H, between tongue and 

 teeth as in TH, or between lips and teeth as in PH or F. 



The vibratives, such as R, are formed by placing the tip of the tongue 

 or the uvula, or the lips, in the path of the blast of air so that they are set 

 into vibration by the blast. In English the vibrative R employed is entirely 

 due to the tongue. 



The sibilants, which may be voiceless as in ' S ' or accompanied with 

 phonation as in ' Z,' consist of continuous noises produced by a narrowing 

 of the path of the air between the tongue and the hard palate. They are 

 therefore similar in production. to the aspirates. In the production of the 

 sound ' L ' the tongue is applied by its edge to the alveolar process of the 

 upper jaw, so that the air or voice escapes by two small apertures in 

 the region of the first molar and between the inner side of the cheek and 

 the teeth. The acoustic characters of these various consonants are still but 

 imperfectly studied. 



