1 88 



NA TURE 



[December 26, 1901 



of the characteristic partial or " formant " is not absolutely 

 fixed. 



The difficulty of harmonising these theories has stiniulated 

 the zeal of many workers, and in particular Dr. Marage' has 

 been remarkably successful in his researches into the nature ol 

 vowels. He first of all criticises the second theory of 

 Helniholtz, pointing out that the failure to reproduce the vowels 

 by synthesis is strongly against it. Thus while, by tuning-forks, 

 the pitch of which is that of the partials of the fundamental tone, 

 oil, and a may be badly reproduced, it has been fnund impos 

 sible to reproduce E and i . He then objects to the theory of 

 Hermann, namely, that the vowel is an oral intermittent and 

 oscillating tone ; first, that the method of recording the vowel on 

 the wax cylinder of the phonograph causes grave errors, because 

 the mouthpiece, lube, air chamber and vibrating disc all 

 profoundly modify the vowel ; second, that the method of 

 analysis by Fourier's theorem assumes that the vowel curves are 

 constituted by superposed simple curves, which is precisely the 

 question at issue, and therefore the argument is a petitio 

 principii ; and third, that the data obtai ned by his method have 



Fig. 19. — Photographic tracings obtained by Blake's method. 



not enabled Hermann to reconstruct the vowels with greater 

 success than Helnihollz. Marage then enters upon his own 

 method, which consists essentially of using a special apparatus 

 constructed on Konig's principle of manometric flames, but so 



optic capsule of Rigollot and Cha 

 > vibrations), f. f, collodion membrane ; 

 a c, stretched between supports A .ind 

 H : /, small cube of india-rubber resting ( 



fLtcKoc, pertain- 

 2ulated by the 



simple as to be practically free from sources of error : that is to 

 .say, there is no mouthpiece, tube or lever. The pictures of the 

 flames were produced photographically by feeding the flame with 

 acetylene gas, and chronophotometrical records were taken with 

 each experiment. He then finds that the flame pictures of i, u 

 and oil show one flame, K, EU and <i two flames, and A three 

 flames. So that the classification of the vowels by flames is 

 exactly that of Grassmann. Each vowel, when all errors have 

 thus been got rid of by simplifying the apparatus, always gives 

 the same picture for any given note. The picture is that of a 

 continuous periodic curve, and the number of periods in a second 

 corresponds to the laryngeal note, while \.ht:form of the period 

 characterises the vowel. With the same vowel the period changes 

 with the note. When the note is near the pitch of ordinary 

 speech, the period varies very little. This is not so when the 

 vowel is sung ; the period then disappears until there is only 

 the laryngeal note. Marage has also by synthesis reproduced 

 the vowels with remarkable success. His first experiments with 



o and A, but not E and I. He ascertained, however, that to 

 reproduce A the resonator must be tuned to the third harmonic 

 or partial of the note on which A was sung ; that to reproduce 

 I., Ki; and o the best result was obtained when the resonator 



Fig. 21. — Tracings obtained by Hermann of vowel o. 



gave the second partial ; and I, u and ou were imitated 

 (but not successfully) when the resonator was in unison with the 

 laryngeal tone. 



Marage finally devised a syren rotated by an electric motor 

 and consisting of a disc having in it a triangular window re- 

 presenting the glottis. The air is driven under pressure through 

 this aperture and then falls on another disc having windows cut 

 out of it in groups according to the nature of the vowel to be 

 synthetically reproduced. Thus the disc for A has four groups, 

 each group consisting of three triangular slit-like windows ; for 

 Oand E thediscshows five groups, e.achconsistingoftwoslits ; and 

 for I and ou there are many slits, without these being atranged 

 in groups. The slits are very large foro and narrow for E, and 

 large for ou and narrow for I. He then moulded a series of 

 casts of the interior of the oral and pharyngeal cavities of a 

 human subject, as these were adapted for the singing of the 

 different vowels, and from them constructed masks or head- 

 pieces which could be placed over the syren so that the air 

 escaping from it passed through the cavities of the mask. 

 He found that if air was driven through the masks under a 

 pressure of only 7 centimetres of water, the timbre of the 

 corresponding vowel was at once perceived, as in whispering. 

 Marage's view is that to form a vowel the true vocal cords vibrate 

 in a horizontal plane, in such a way as to influence by their 

 greater or less degree of approximation the escape of air. 



If the air escapes in three little puflfs as it were (the 

 cords vibrating during each puff a number of times equal to the 

 pitch of the note on which the vowel is spoken or sung), so that 



— Rops' apparatus for the analysis of vowel-tones. 



there are intervals between the groups of puffs, then the vowel 

 A is the result. The oral re.sonator is in unison with the sum 



resonators were not quite satisfactory ; he could reproduce ou, I of the vibrations and the vowel is emitted. If the resonator 

 1 M.-iragc: "Thdoricde la Formation desVoyelles.'i?/. (jV I (either artificial or ihe oral cavity, as in life) is turned to the 



NO. 1678, VOL. 65] 



