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
Sound of a Living Heart Sound of a Living Heart Sound of a Living Heart is tenth studio album by JJ Heller. Stone Table Records alongside Sparrow Records released the album on August 21, 2015. Kevin Sparkman, indicating in a three and a half star review for "CCM Magazine", describes, "Heller continues her proven formula of innocent melodies, heart moving lyrics, and inviting musical moments." Awarding the album four stars from Jesus Freak Hideout, Mark D. Geil states, ""Sound of a Living Heart" is an encouraging sign of a continued upward trajectory." Jay Heilman, reviewing the album for Christian Music Review, writes, he's "highly impressed..."Sound