Male cicadas produce their characteristic calls with a ribbed organ called a tymbal.
A tymbal is a stiff, corrugated membrane on the side of the abdomen. Muscles buckle it inward and release it rapidly, creating a series of clicks. The cicada’s hollow abdomen and surrounding body tissues help amplify and shape those clicks into the loud calling song heard from trees.
Only male cicadas normally produce the familiar loud calling song. It attracts females and may also help males interact with one another. Females lack the same sound-producing tymbal system and can respond to male calls by flicking their wings.
The tymbal is not an ear. Cicadas have hearing organs called tympana, which detect sound, while the tymbal generates it. The similar names cause frequent confusion. A cicada’s call is also not made by rubbing body parts together, the method called stridulation in crickets and katydids.