Resumen de The physics of Tibetan singing bowls

Luís Henrique, José Antunes, Octávio Inácio

• Tibetan bowls have been traditionally used for ceremonial and meditation purposes, but are also increasingly being used in contemporary music-making. They are handcrafted using alloys of several metals and produce different tones, depending on the alloy composition, their shape, size and weight. Most important is the sound producing technique used - either impacting or rubbing, or both simultaneously - as well as the excitation location, the hardness and friction characteristics of the exciting stick (called puja). In this paper, we extend to axi-symmetrical shells - subjected to impact and friction-induced excitations - our modal techniques of physical modelling, which were already used in previous papers concerning plucked and bowed strings as well as impacted and bowed bars. Our simulation results highlight the existence of several motion regimes, both steady and unsteady, with either permanent or intermittent bowl/puja contact. Furthermore, the unstable modes spin at the angular velocity of the puja. As a consequence, for the listener, singing bowls behave as rotating quadropoles. The sound will always be perceived as beating phenomena, even if using perfectly symmetrical bowls.