Experimental investigation of lip-specific mouthpiece forces and pressure parameters in trombone performance under realistic playing conditions

Mastering brass playing depends on the fine control of the embouchure–the coordinated interaction between lips, mouthpiece, and airflow. While teachers and performers have long emphasised this balance, objective data on how lip forces and pressures interact during real performance are scarce. This study addresses this gap by introducing a novel sensor-integrated mouthpiece system capable of directly capturing lip-specific forces together with mouthpiece and intraoral pressure signals during playing. Data from 31 trombonists, ranging from beginners to professionals, were synchronised with score annotations and analysed note by note. Distinct embouchure strategies emerged across proficiency levels: advanced and professional players maintained tighter control of total and differential lip forces, operated within narrower limits, and showed greater relaxation during rests. At note onsets, they exhibited smaller relative force surges and more balanced lip contributions, reflecting a potential refined motor coordination. These findings provide the first quantitative, lip-resolved evidence of force magnitudes, distributions, and efficiencies across skill levels, offering new perspectives for brass acoustics, pedagogy, and feedback-based training.