ARTIFICIAL VOWELS. 815 



membranes, the vocal cords ( 312). In uttering the various vowels the mouth assumes a 

 characteristic form, so that its cavity has a certain fundamental tone peculiar to itself. Thus, 

 to the fundamental tone of a certain pitch produced within the larynx, there are added certain 

 overtones, which communicate to the laryngeal tone the vocal or vowel quality. Hence, a 

 vowel is the timbre or quality of a musical tone which is produced in the larynx. The quality 

 depends upon the number, intensity, and pitch of the overtones, and the latter, again, depend 

 on the configuration of the "vocal cavity in uttering the different vowels ( 317). 



Suppose a person to sing the vowels one after the other on a special note, e.g., b b, we can, 

 with the aid of resonators determine the overtones, and in what intensity they are mixed with 

 the fundamental tone, b b, to give the characteristic quality. According to v. Helmholtz, 

 when we sound the vowels on b b, for each of the three vowels, one overtone is specially 

 characteristic for A-b 11 b; for O-b 1 b; for U-f. The other vowels and the diphthongs have 

 each two specially characteristic overtones, because in these cases the mouth is so shaped that 

 the posterior larger cavity, and also the anterior narrower part, each yields a special tone 

 ( 316, I. and E). These two overtones are for E-B 1 " b and fl ; for I-d iv and f ; for A-gW and 

 d 11 ; for O-c 111 $ and f ; for U-g 111 and f. These, however, are only the special upper tones. 

 There are many more upper tones, but they are not so prominent. 



Artificial Vowels. Just as it is possible to analyse a vowel into its fundamental tone and its 

 upper tones, it is possible to compound tones to produce the vowels by simultaneously sounding 

 the fundamental tone and the corresponding upper tones. (1) A vowel is produced simply by 

 singing loudly a vowel, e.g., A, upon a certain note against the free strings of an open piano, 

 whilst by the pedal the damper is kept raised. As soon as we stop singing, the characteristic 

 vowel is sounded by the strings of the piano. The voice sets into sympathetic vibration all 

 those strings whose overtones (in addition to the fundamental tone) occur in the vocal com- 

 pound tone, so that they vibrate for a time after the voice ceases (v. Helmholtz). (2) The 

 vowel apparatus devised by v. Helmholtz consists of numerous tuning-forks, which are kept 

 vibrating by means of electro-magnets. The lowest tuning-fork gives the fundamental tone, 

 B b, and the others the overtones. A resonator is placed in front of each tuning-fork, and 

 the distance between the two can be varied at pleasure. The resonators can be opened and 

 closed by a lid passing in front of their openings. When the resonator is closed, we cannot 

 hear the tone emitted by the tuning-fork placed in front of it ; but when one or more resonators 

 are opened the tone is heard distinctly, and it is louder the more the resonator is opened. By 

 means of a series of keys, like the keys of a pianoforte, we can rapidly open and close the re- 

 sonators at will, and thus combine various overtones with the fundamental tone so as to pro- 

 duce vowels with different qualities. V. Helmholtz makes the following compositions : 

 U = B b with b b weak and fl ; = damped B 9 with b 1 b strong and weaker b b, f, d i! ; A = b b 

 (fundamental tone) with moderately strong b 1 b and f", and strong b 11 band d fii ; A = b b 

 (fundamental tone) with b ! b and f I somewhat stronger than for A, d strong, b ! b weaker, d 1 ' 1 

 and f 111 as strong as possible ; E = b b (as fundamental tone) moderately strong, with b ! b and f 1 

 moderate also, and i l ''\ a 111 b, and b !!l b> as strong as possible; I could not be produced. 



In Appunn's apparatus, the fundamental tone and the overtones are produced by means of 

 organ pipes, whose notes can be combined to produce the vowels, but it is not so good as the 

 tuning-forks, since the organ pipes do not yield simple tones, but nevertheless some of the 

 vowels can be admirably reproduced with this apparatus. 



Edison's Phonograph. If we utter the vowels against a delicate membrane stretched over 

 the end of a hollow cylinder, and if a writing style be fixed to the centre of the membrane, and 

 the style be so arranged that it can write or record its movements on a piece of soft tinfoil 

 arranged on a revolving apparatus, then the vowel curve is stamped as it were upon the tinfoil. 

 If the style now be made to touch the tinfoil while the latter is moved, then the style is moved 

 it moves the membrane, and we hear distinctly by resonance the vowel sound reproduced. 



[Koenig's Manometric Flames. By means" of this apparatus the quality of the vowel sounds 

 is easily shown. It consists of a small wooden capsule, A, divided into two compartments by 

 a piece of thin sheet india-rubber. Ordinary gas passes into the chamber on one side of the 

 membrane, through the stop-cock, and it is lighted at a small burner. To the other compart- 

 ment is attached a wider tube with a mouthpiece. The whole is fixed on a stand, and near it 

 is placed a four-sided rotating mirror, M, as suggested by Wheatstone (fig. 598). On speaking 

 or singing a vowel into the mouthpiece, and rotating the mirror, a toothed or zigzag flame- 

 picture is obtained in the mirror. The form of the flame-picture is characteristic for each 

 vowel, and varies of course with the pitch.] [Fig. 599 shows the form of the flame-picture 

 obtained in the rotating mirror when the vowels, ou, o, a, are sung at a pitch of ut x , sol-^, and 

 ut 2 . This series shows how they differ in quality.] 



[Koenig has also invented the apparatus for analysing any compound tone whose funda- 

 mental tone is ut 2 (fig. 600). It consists of a series of resonators, from ut 2 to ut 5 , fixed in an 

 iron frame. Each resonator is connected with its special flame, which is pictured in a long 

 narrow, square rotating mirror. If a tuning-fork ut 2 be sounded, only the flame ut 2 is affected, 

 and so on with each tuning-fork of the harmonic series. Suppose a compound note containing 



and those of 



