David C. Copley
William J. Strong
Dept. of Phys. and Astron., Brigham Young Univ., Provo, UT 84602
More than 50 years ago, Martin investigated lip vibrations in a coronet mouthpiece using stroboscopic photography [D. Martin, J. Acoust. Soc. Am. 13, 305--307 (1942)]. Since then, several researchers have based lip models on Martin's data. Unfortunately, due to the quality of the photographs, it is difficult to obtain anything more than a limited quantitative description of the lip motion. The purpose of this study is to obtain more detailed photographic sequences and lip motion data on which new models may be based. The trombone was selected as representative of the lip reed family. A computer-controlled fiber optic stroboscope was used to capture the motion of a player's lips on video. By inserting the optic bundle through small holes drilled in the mouthpiece, lip motion was observed from the front and side for six notes (B(flat)2, F3, B(flat)3, D4, F4, G4) played at loud and soft dynamic levels. Video sequences and resulting lip motion data will be presented and discussed.