Cinematographic annual : 1930 (1930)

300 • CINEMATOGRAPHIC ANNUAL largely dependent on the volume and the elastic properties of the air. In wind instruments with reed mouthpiece, the reed vibrates and thus generates a series of air pulses which are regulated and resonated by the air column. In the human voice the vocal cords resemble this action somewhat, with the additional feature of muscular control, which adjusts the rate of vibration. In the cupped mouthpiece instruments, the stretched lips play a similar role, with the help of the tongue. In all cases the final tone elicited by the instrument is composed of a fundamental along with a series of overtones or partials. These latter are present in varying intensities, sometimes even greater than the fundamental. With the flute the fundamental is very strong, the second and fourth partials are somewhat prominent and the remainder very weak. The clarinet shows a fair intensity for the fundamental along with strong eighth, ninth, and tenth partials. The oboe has weak fundamental and strong fourth and fifth, weak sixth partials. The brass horns often show many upper partials of considerable intensity. These mixtures of partials make the various instruments have their characteristic quality and if the recording and reproducing change the relative intensities, the resulting sound does not have fidelity. The resonating qualities of the mouth and throat are strikingly illustrated by the use of the artificial larynx. This is a small vibrating reed device which is supplied with air pressure from bellows and inserted in the mouth of persons who have lost the larynx due to surgical operation. The vibrating reed pipe arrangement supplies the air pulses and if the person regulates FIGURE 8