Vibration of the Clarinet Body and its Contribution to the Clarinet Tone

An artificially blown clarinet with all its tone holes closed was coupled tightly to one end of a large metal pipe so that all the sound produced was radiated into the pipe. Porous urethane foam stuffed into the other end absorbed the sound while allowing sufficient steady air flow to operate the clarinet. The internal sound wave in the instrument was monitored by means of a microphone in the mouthpiece. Under these conditions, the clarinet was practically inaudible; the level as read on a General Radio SPL meter placed nearby increased only two to three dB above the laboratory background of about 46–48 dB, and this increase was mostly due to sound radiated from the pipe rather than from the clarinet body. By using plastic tube in place of the more‐rigid clarinet body, the sound radiating from it could be approximately measured, and was found to be some 45 dB below the sound radiated in the normal manner under the same blowing conditions when the sound‐absorbing pipe was removed. It appears that the vibration of the clarinet body has no effect whatever on the tone of the instrument.