I just came across the below YouTube video, coincidentally a couple of days after bringing this research up to Paul T. and not being able to remember the name of the author. Jay Bulen, now professor of trombone at Truman State University, filmed trombonists’ embouchures using a camera and strobe light set up inside the mouthpiece to study the lip motion while buzzing. This video shows the lips of Peter Ellefson, who teaches trombone at Indiana University.
One of Bulen’s test subjects, whose name I’ve forgotten, sent me the video footage of his embouchure while I was researching for my dissertation. Because you don’t get to see the embouchure formation from the outside, it’s hard to put these videos into context to determine a player’s embouchure type, but in the case of Ellefson’s embouchure it looks like the upper lip predominates, so his embouchure must be one of the downstream types.
Bulen’s research, titled Synchronized Optical and Acoustical Measurements of Trombone Embouchure, was published in the The Journal of the Acoustical Society of America. Here’s the abstract:
Outward striking‐ and inward striking‐reed models have been proposed for representing brass players’ lips [Sanoyesi etal., Acustica 62, 194–210 (1987)]. The models differ in the predicted relationship between mouthpiece pressure and lip displacement. To investigate this, Yoshikawa measured the phase relationship between mouthpiece pressure and lip strain as indicated by a strain gauge taped to the upper lip [J. Acoust. Soc. Am. 97, 1929–1939 (1995)]. However, the relationship between strain and displacement have not been experimentally established, and Yoshikawa’s assumed correspondence ‘‘is still a hypothesis which needs refinement’’ (p. 1931). Optical measurements are required. Synchronized optical and acoustical measurements of a trombonist’s embouchure have been made under performance conditions, using an adaptation of techniques described in Sercarz etal. [Am. J. Otolaryngol. 13, 40–44 (1992)]. Using strobed videoscopy, individual video fields are coordinated with mouthpiece pressure by means of timing signals. The phase relationship between mouthpiece pressure and lip displacement will be reported for a variety of fundamental frequencies and intensities. In addition, estimates will be presented of the aperture area and the mouthpiece volume swept out by the lips.The goal of this informal workshop, a continuation of Session 1aSC, is to bring together several researchers working on various aspects of voice perception. Historically, the study of voice has been treated as a more‐or‐less autonomous area quite distinct from other research problems in speech and hearing sciences. In this workshop, some of the traditional problems of voice classification and perception will be discussed and reviewed and then these efforts will be related to recent findings in speech perception and spoken word recognition which have shown important dependencies between traditional voice parameters and perceptual analysis of the speech signal.