The effect of wall material on the structural vibrations excited when lip-reed instruments are blown

The question of whether the wall material plays a significant role in determining the timbre of a lip-reed instrument has been the subject of much discussion. The most likely way is through its influence on the structural vibrations of the instrument. In this paper, the wall vibrations of five post horns of identical geometry and surface finish but manufactured from different copper alloys are studied. The structural resonances of each post horn are first established by mechanically exciting the post horn under test and measuring the vibration amplitudes along the length of the instrument using a Laser Doppler Vibrometer. Next, the wall vibration amplitudes induced when the five post horns are artificially blown are measured. Finally, these induced wall vibrations are compared with each other and then related to the structural responses of the instruments.