Research response to 1997 survey published in “Selected Pedagogical Practices of College Instructors of Flute, Clarinet and Saxophone”:
The final aspect of the survey investigated vibrato production for flute, clarinet, and saxophone. It is interesting that most flutists reported utilizing either their diaphragm or a combination of the throat and diaphragm to produce vibrato. In recent years many flutists have tried to clarify the misconception that flute vibrato is produced with the involuntary diaphragm muscle. Instead, the production of vibrato is produced by pulsing the abdominal muscles in conjunction with the throat muscles and speed of the vibrato. Although several instructors commented that they did not feel vibrato was appropriate on the clarinet, those who do use vibrato reported that pitch fluctuation on clarinet is mainly executed with the jaw/lip. Most commonly, saxophonists reported that vibrato is produced with either the jaw/lip or through a combination of jaw/lip and throat alterations.
Additional research, experiential observations and suggestions:
-contrary to many teachers’ and performer’s perceptions, Flute vibrato is produced by pulsing the air via the lower throat muscles (not the upper throat muscles) in conjunction with constant abdominal/diaphragmatic support; it is not produced by pulsing the large diaphragmatic muscles
-on Flute, it is common and correct technique, for the cheeks to vibrate in sympathy with air pulsations
-jaw vibrato should never be used on the Flute
-vibrato on Clarinet, when used, is mainly executed with jaw/lip pressure changes on the reed
-vibrato on Saxophone, essential to all styles of music on the instrument, is also mainly executed with a change in jaw/lip pressure, although some performers may also find the throat muscles are also somewhat involved