Electronic wave sharing synthetic sound system

Abstract

An electronic sound system especially effective with bell sounds synthesizes the approximate sound of each bell in a set of 49 switch operated bell sounds. The synthesizing is accomplished by utilizig an envelope generator for each partial of a group of 7 partials for each of the 49 sounds, in association with a single 73 note wave generator. The envelope generators for low partials of each group of 7 are slow attack, slow decay relatively long envelopes. The envelope generators for the high partials of the same group of 7 are fast attack, fast decay relatively short envelopes, and envelopes for certain intermediate partials are fast attack with combined short and long decay envelopes of intermediate length. There is a single wave generator for each of 73 tones, the wave generators having circuits interconnecting them with partials of common frequency of the various groups of 7 partials for the respective keys. There is a special resistor diode matrix for each key consisting of 9 resistors and corresponding diodes for the respective 7 partials. Two of the partials have compound envelopes. Then with the partials of common frequency being interconnected with wave generators of common frequency, the wave generator output is shared in a way such that when two keys are closed simultaneously and certain partials are of the same frequency, those certain frequencies are reproduced at increased output power making the resultant bell sound more realistic.