Note 149 — Chapter IV · PHONOLOGY AND SEMATOLOGY.

See Sievers: “Grundzüge d. Lautphysiologie” (1876), p. 19. This explanation of the causes of this difference between the two kinds of voice (true and falsetto) is due to the observations of Garcia. Various theories had previously been put forward to account for it. J. Müller thought that in producing chest notes, the whole breadth of the vocal chords vibrated, only their thin inner margins in producing falsetto notes. Mayo and Magendie held that the falsetto notes are produced by the vibrations of only one-half the length of the vocal chords, when the glottis is partially closed; G. Weber that they are due to the vibration of the chords in segments, separated by nodal points, so that harmonics of the fundamental note are formed. Pétrequin and Diday maintained that they are produced by the vibration of the air itself in the glottis, without any movement on the part of the vocal chords, while Wheatstone thought that they are formed by the division of the air in the trachea into harmonic lengths, the tone produced by the vocal chords being thus reciprocated, since, besides vibrating by reciprocation with a sonorous body, the vibrations of which are isochronous with its own, a column of air may also vibrate by reciprocation in its several lengths, the number of its vibrations being in this case a multiple of those of the sonorous body.