1917] 



on Experimental Phonetics 



15 



There are several ways of recording mechaincally the presence or 

 absence of voice. The method which .2:ives the most satisfactory 

 results from the point of view of the hnguist consists in using a 

 kymograph fitted with one or more tambours of Marey's model. 

 The Marey tambour is a mechanism by which vibrations of air are 

 communicated to an elastic membrane and thence to a very light 

 recording needle. The vibrations of the recording needle are 

 generally recorded on a revolving drum covered with smoked paper, 

 or some similar contrivance. The most useful type of tambour is 

 one with a perished rubljer membrane, 3 cm. in diameter. 



^ Air-waves set up by speech may be communicated to a tambour 

 (1) from the mouth (by speaking into a mouth-piece) ; (2) from the 

 nose (by using a " nasal olive ") ; or (3) from the outside of the larynx 

 (by using a " larynx capsule.") 



Fig. 11. — Mouth-Tracing of potato. Below is a tracing of a 

 tuning-fork giving 100 vibrations per second. 



B 



Fig. 12. — Mouth-Teacings of (A) English buckle (Male Voice)- '\ 

 AND (B) French boucle (Female Voice). ,-.iJ 



Note the unvoicing of the French I, and the length of the k. 



[A kymograph with all fittings was shown. A kymographic 

 tracing of the word put was made on a piece of smoked glass and 

 shown on the screen.] 



The nature of these kymographic speech-curves can be demon- 

 strated to a large audience by substituting a very small mirror for the 

 tambour-style and directing a powerful beam of light on to it in 

 a darkened room. This beam of light must be reflected from the 



