Method
By closing the back of the throat, a choked-off sound can be achieved. This is rather abrupt, and often results in a slight sforzando articulation once released, due to the release of pressurized air from the lungs.
Necessary information
This is not a comfortable technique to perform, although it is relatively easy to perform. The speed at which it can be achieved is also on the slow side, due to the physical constraint inherent in its performance. Utilizing this technique with a large amount of force can be physically exhausting, which may also be uncomfortable for some performers; caution is recommended when using this technique extensively.
Notation
The author has not personally seen this technique used extensively in the contemporary repertoire, and there are no standardized ways to notate its use. Any consistently-applied notation that clearly indicates the technique is acceptable. In the provided example, the note that is “stopped” with the glottal motion is notated as a hollow notehead, which clearly demonstrates which notes are affected. A similarly-clear notation is recommended for other uses of this technique.
Relative Difficulty
Advanced to Professional
Works to consider (bolded titles are particularly representative examples of this technique)
Solo Tuba Music – Cort Lippe
Tube space – Dmitri Kourliandski
The Composer's Guide to the Tuba 