Statistical analysis was made of the variability of the distribution of orchestral sounds and an experimental formula is given for the coefficient of variation of measured per-cent-of-time of the distribution against measurement duration and level. A pair of constants included in this formula gives a quantative measure of the slow level-variations of the pressure distribution for the individual orchestral music depending on conductors. A list of these constants obtained for 21 representative orchestral music is presented.
Cantilever Configurations are widely used for relay, switch and spring systems. It is important to control damping of a cantilever as well as the natural frequency as desired in order to prevent chattering. By providing damping layers, the damping and the natural frequency are more easily controlled by means of the combination. The purpose of this paper is to discuss theoretically the natural frequency and the viscoelastic damping of sandwich cantilevers. Two types of construction are considered. It was found that as frequency increases or as thickness-length ratio of cantilevers increases, the transverse shear deformation in the core plays an important role for the damping as well as for the natural frequency in one case, while the general flexural behaviour is responsible for the damping in another case.
As a suitable measure of the quality of the electro-acoustic transducers, the concept of Betriebsdampfung has been proposed. One of the authors defined effective power Betriebsdampfung based on a real power of the signal in place of the conventional Betriebsdampfung and showed that in both cases it is appropriate to design an electro-acoustic transducer so as to decrease its Betriebsdampfung. From this point of view, studies of the practical transducers were made. The investigation on this point has been insufficient. In this paper, we defined an operational parameter which is expressed as the ratio of the force factor to the geometrical mean of the electrical and the mechanical impedances. Analysis was made when this parameter varied in the complex domain under a complete matched condition. Several graphs were drawn which would be useful for the practical design of the electro-acoustic trasducers. Evaluation of the operational parameter on the practical transducers were also discussed.