The vibration and/or oscillation in bell shaped objects (horns, bells, etc.) set in periodic motion.
Bell tuning - https://youtu.be/3EVCHyqh42w?si=6jg9FEUl0L-hT7E2
See Also
07 - Resonance Co-vibration or Sympathy of Tones
cavity resonator
Bell Resonance
Figure 18.03 - Keely Chart Showing Acoustic Resonance of the Brain Chord
Resonance
Resonance Box
resonator
Sympathetic Resonance