Sound amplification by stimulated emission of radiation phenomenon, known as the Larsen effect, is the result of a positive feedback. In general, every oscillator consists of three main parts. These are the power source or pump, the amplifier and the positive feedback leading to the output. The corresponding parts in a SASER device are the excitation or pumping mechanism, the active (amplifying) medium, and the feedback leading to acoustic radiation. Pumping can be performed, for instance, with an alternating electric field or with some mechanical vibrations of resonators. The active medium should be a material in which sound amplification can be induced. An example of a feedback
A Moving Sound York City – 2007 Ollin Kan Festival, Mexico City -2007 The Quebec City Festival, Canada -2007 Grassroots Festival, Ithaca NY – 2007 Chicago World Music Festival – 2007 WOMEX, Music Exposition Spain – 2006 MOFFOM Festival, Prague, CZ – 2006 The New York Public Theater – 2006 A Moving Sound A Moving Sound () or Sheng Dong is a Taiwanese music act consisting of vocalist/dancer Mia Hsieh, vocalist, bass guitarist and zhong ruan player Scott Prairie, erhu player I-Fang Chen, and zhong ruan player Chih-Ling Chen. In A Moving Sound’s music traditional Taiwanese music forms are reinterpreted to create new