The mechanism having the cicadas in their body to sing quite complicated. The organs that produce sound are called tymvala. The tymvala is a pair of bar membranes in the abdominal base. The sound is created by the coupling of internal muscles of tymvalou. This causes the membranes to bend inward, creating their distinctive sound. When the muscles relax, the tymvala turn over in their original position. Scientists still do not fully understand how this device produces such a loud sound.