Ultrasound of Circular Breathing
Circular breathing is a technique used to play long, continuous tones with a wind instrument such as an Australian didgeridoo. A continuous outflow of air is created by snatching quick breaths through the nose while the tongue blocks off the oral cavity and simultaneously expelling air from the oral cavity by pushing the tongue forward and constricting the cheeks. The first video shows the didgeridoo player in the ultrasound apparatus at Maureen Stone’s laboratory at the University of Maryland School of Dentistry.
The second video shows the ultrasound recording. Note the timing between the audible “sniffs” and cheek inflation (just prior to the sniff) and deflation (during the sniff). Deflation of the cheeks is coupled with a forward push of the tongue; together these movements force air out of the oral cavity while inhaling is occurring via the nose, thereby maintaining continuous air outflow without running out of breath.
[Videos created in collaboration with Dr. Stone and members of her lab.]
Performance on brass (and other wind) instruments requires articulatory movements similar to coronal consonants used in speech production and teachers have long used speech syllables to demonstrate what students should do with their tongue during brass playing. In his PhD thesis, lab member Matthias Heyne (himself a studied bass trombonist) investigated the influence of native language on playing brass instruments, uncovering some evidence that motor memory from a player’s native language affects tongue position during sustained note production, although no direct mapping onto vowel tongue positions (as suggested by the pedagogical literature) was found.
In the first video, you can see Matt Allison of the New Zealand Symphony Orchestra performing the trombone solo from Ravel’s famous Bolero. The ultrasound video in the background shows the surface of his moving tongue as a white line within the wedge-shape scan area imaged by the ultrasound probe placed underneath his jaw and held in place by a custom-made jaw brace. The front of Matt’s tongue is at the right and you should be able to see how his tongue moves upward to contact the alveolar ridge when beginning a note (unless notes are slurred). Unfortunately, ultrasound imaging does not provide any anatomical landmarks making it hard to determine the position of the tongue surface in relation to other oral structures. During sustained notes, it might seem like the tongue assumes a vowel-like position; however, it becomes clear that this is not the case once one overlays averaged traces of the playing position onto vowel productions from speech.
In the second video, you can again see Matt Allison performing an orchestral excerpt, this time a passage from Rossini’s La Gazza Ladra.