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Сообщение от michael
А значит, что обратная отдача колебаний от корпуса в воздух столь мала, что ... ею можно пренебречь.
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In a 1964 experiment, University of Southern California physicist Dr. John Backus attempted to determine the role of a clarinet’s body vibrations in sound production.5 Backus’s experiment centered on a clever and slightly comical gadget, with an artificial embouchure powered by a household vacuum cleaner. The clarinet’s tone holes were all closed (simulating a clarinetist playing the instrument’s lowest note), and the bell of the instrument was fitted with a muting device. When the clarinet was “played” via vacuum cleaner in this way, no sound waves could pass from the air column inside the clarinet directly into the air surrounding the instrument. Backus found that in this situation the instrument was virtually silent; the vibrating wood of the clarinet emitted such weak sound waves as to be inaudible to a human ear at a distance of one inch from the instrument’s body. Backus concluded that the wall vibrations of a clarinet are too small to produce a perceptible sound. Further, he speculated that if it were possible to make the instrument vibrate sufficiently to be heard, the consequence would not likely be a pleasant one; he pointed out that a similar phenomenon occurs when one of the instrument’s keys works loose and causes an annoying buzz. Backus’s further research reveals that the instrument’s body vibrations are due to the reed vibrating against the mouthpiece, not due to the vibrations of the enclosed air column.6