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
The Sound of a Flower Jin Chae-seon". The Sound of a Flower The Sound of a Flower () is 2015 South Korean period drama film based on the life of Jin Chae-seon, who became Joseon's first female "pansori" singer in 1867. Jin risks her life by cross-dressing as a man, at a time when women were forbidden to sing in public or perform on stage. The film focuses on the relationship between Jin and her pansori teacher, Shin Jae-hyo. The Korean title, "Dorihwaga", is a song written by Shin about his protégée after she became a court singer. The film was directed by Lee Jong-pil,