Abstract
Here, two experiments were carried out on the attack transient of pure tones, with special regard to the differences in tone quality of natural musical instruments and an electronic musical instrument. In this paper, we refer to the results of the second experiment. The details of the first experiment are mentioned in a separate paper. In the first section in order to examine the auditory characteristics of 34 clusters, classified mathematically in part 1, a sound synthesizer was constructed, which can generate various attack forms at will so far as the quantized time and intensity are concerned. By selecting several representative patterns from each cluster, experiments were carried out to examine, (1) whether the patterns classified into different clusters are auditorily different or not, and (2) whether the patterns classified into the same cluster are judged to be very similar or not. The results, as shown in Fig. 2 and Fig. 3, indicate that (1) the 34 clusters may be re-classified into eight groups, and (2) most of the patterns within the same cluster are judged to be of the same quality. Second, although the experiment in part two is carried out with sound synthesizers, future simulation research should be made by means of a digital computer. In order to synthesize these attack transient patterns with digital computers, formulation has been attempted in terms of a cascaded exponential function and a step function of eight groups of patterns. The formulae are shown in Table 2. As pointed out at the outset, the attack pattern of overtones for natural musical instruments can vary independently. In the design of tone quality of electronic musical instruments, one must take into consideration such phenomena. Digital computers will show a greater degree of freedom in this respect.
