| 摘要 |
PURPOSE:To obtain an electric sound source close to the acoustic characteristics of a natural musical instrument by transducing mechanical vibration from a mechanical sounding source into an electric signal through a filter means which extracts a prescribed discrete frequency band and feeding it back to the mechanical sounding source positively. CONSTITUTION:When a speaker 37 as the sounding source generates a sound with specific frequency characteristics with a switch 31 on, a sound wave of specific frequency is extracted by the mirocphone 38 through the columnar resonance in a resonance pipe 51 and converted into an electric signal, which is outputted to an amplifier 33. The amplifier 33 amplifies the output electric signal and supplies it to the speaker 37 again, thus constituting the positive feedback circuit. Consequently, a discrete sound which has high output sound pressure in the specific frequency band with respect to frequency characteristics is obtained and this is close to a natural sound and sent out of the speaker 41 through an amplifier 43. |
