Progress Report on Violin Research Free

In continuation of work previously reported several items of progress may be mentioned. The effect of the air‐body on the tone has been studied by three methods, which agree in showing that the air‐body makes no considerable contribution to the tone except at the frequency of its fundamental vibration. The effect of the varnish has been studied on one instrument with results confirming those of Meinel: adding the varnish makes no important change in the response curve and only 1.5 percent change in the weight. The varnish slightly increases the damping for high tones. Changes in atmospheric humidity such as are usually encountered (20 to 70 percent) alter the weight of a violin by only 2 percent and do not affect any of its dimensions materially excepting its thickness near the bridge. This alters the stresses near the sound post and causes minor changes in the natural responses. The vibrations of the bridge have been studied by Minnaert. We are finding that the dimensions of those parts of the bridge which transmit vibrations from the strings to the feet are important and must be considered in addition to the mass of the bridge as a whole. Unsymmetrical loading of the bridge affects most the energy of those vibrations entering the body via the loaded part. Changes in the tension in the strings when symmetrical do not seem to alter the frequency of the natural responses, but when they are unsymmetrical the peaks are shifted. Transient effects in the growth or decay of a violin tone are being studied. The phases of harmonics with reference to the fundamental are found to change in a complicated way which deserves further examination. Oscillations of energy between string and body sometimes occur while the sound is decaying. The damping of the air‐body can be measured, and that of some of the main body‐resonant tones may be found. The damping of high harmonics is much more than that of the fundamental.