Patent ID: 8115092
Filing Date: 2012-02-14
Classification: G10H

Abstract:
1. A method of simulating acoustic tones produced through an acoustic musical instrument having at least one vibratory wire and a vibratory instrument body provided with supporting portions through which said at least one wire is supported for producing a tone signal representative of artificial tones close to said acoustic tones and observed at a certain point in the air, comprising the steps of: a) acquiring a first piece of data expressing force exerted on said at least one vibratory wire and a second piece of data expressing a displacement at each of said supporting portions; b) determining a third piece of data expressing a displacement of said at least one vibratory wire on a modal coordinate system for each natural vibration mode and calculated by using an equation of motion defining relation between said first piece of data and said second piece of data and said third piece of data, c) determining a fourth piece of data expressing force exerted on the supporting portions by said at least one vibratory wire and calculated by using a direction cosine among the coordinate axes and equations defining relation between said second piece of data and said third piece of data and said fourth piece of data, d) determining a fifth piece of data expressing a displacement or a velocity of said vibratory instrument body on said modal coordinate system approximated to a proportional viscous damping system on the basis of said fourth piece of data and a sixth piece of data expressing a natural angular frequency, a modal damping ratio and components of natural vibration modes of said vibratory instrument body by using an equation of motion defining relation between said forth piece of data and said fifth piece of data; e) determining said second piece of data as a sum of products among values of said fifth piece of data, natural vibration modes of said vibratory instrument body at said supporting portions and said direction cosine among the coordinate axes; f) supplying said second piece of data to said step a); g) determining a seventh piece of data expressing a sound pressure radiated from said vibratory instrument body and observed at said certain point in the air on the basis of said fifth piece of data as a sum of calculation results through a convolution between a velocity of said vibratory instrument body on said modal coordinate system and an eighth piece of data expressing an impulse response or a frequency response between said velocity of said vibratory instrument body on said modal coordinate system and said sound pressure at said certain point in the air; and h) producing said tone signal representative of said seventh piece of data and expressing said artificial tones.