The Timbal is a term for a vibrating membrane in the abdomen of a male cicada, which is responsible for the characteristic sound produced by the insect.


A pair of timbals are located on the sides of the abdominal base and when vibrated rapidly, enlarged chambers derived from the trachea make the cicada's body serve as a resonance chamber, greatly amplifying the sound.


Some cicadas produce sounds louder than 106 decibels, among the loudest of all insect produced sounds.