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-sound Best Sound ). A-Sound put out their debut album in July 2008: Release. It was the first Mongolian rock album to feature some songs in English. The album featured many popular songs, including: "Uyanga," "Shine On," and "Forever." "Uyanga" is a popular girl's name and is a pleasant song sung in Mongolian. "Shine On" and "Forever" are two slices of immaculate pop song-craft, and to music critic (among other things) Brian Offenther, should have been international pop smashes. In "Forever," lead singer Temuulen's crystal clear voice really sours. In early 2009, a deluxe version of Release was put out and