The true nature of speech: With application to a voice-operated phonographic alphabet writing machine

That speech is a rapid variation in intensity of the voice and mouth-tones according to definite sound patterns called letters of the alphabet, is proved, by showing that speech is the result of action of the mouth-parts in varying the intensity of the voice and mouth-tones, and through photographs taken with the string-galvanometer of each letter sound of the alphabet, showing definitely the characteristic variation in intensity of tone for each letter of the alphabet. From the curves, the phonographic alphabet is obtained by measuring the variations in intensity of the main tone of the record. A design for a voice-operated phonographic alphabet writing machine is described. The object of this device is to record speech automatically in ink on paper in the form of an easily read compact system of natural characters called the phonographic alphabet. Its design comprises a high-power telephone transmitter controlling electric resonator circuits, the intensity of currents in which is measured by the vibration of mirrors reflecting light upon a selenium cell connected to a special recording pen.