Udukku is again a double headed percussion instrument belonging to the Membranophone family. It is an instrument of Tamil origin, similar to Damaru and Idakka. Udukku is slightly larger than Damaru but smaller than Idakka. It has an hour-glass shape. It is used in Kerala, Tamilnadu and eastern parts of Sri Lanka. Udukku normally is played in folk culture or sometimes along with some temple rituals. It is also known as Udakkai
The Udukku is about 10 inches long with 6 to 8 inches of diameter at the ends and having a tapering (towards centre) body. A single hollow block of Jack wood tree is used in making the body of Udukku. Goat Skin leather is used to cover the ends of Udukku across its mouth. Hoops are placed on the edge of the body. Strings are used to tighten the skins.
Udukku is played on one side by hand and a strap made of cloth is fixed to the middle of the instrument for clasping it. The fingers are used along with the inner palm are used for playing Udukku. Pitch modulation is achieved using adjusting the tension of the skins by squeezing and releasing of the strap.
Udukku is used for Ayyappan Pattu in Kerala, known as Udukku Kotti Pattu. Udukku is used along with Vocal singing during the Ayyappan Pattu.