Dammam is a large drum in one piece. The drum is covered with goatskin, which is secured by a cord, which is knotted seven times, and made from the fibers of a date palm.

It is played with a wooden stick and/or with the hand. In the south of Iran it is played in religious ceremonies and kept in the Mosque.

in some other books it is told that bar means “like” Bat means “duck”, so the similarity between the form of a Barbat and the chest of a drake is the other reason for its name.

After Islam’s attack to Iran this instrument was taken to Arabia and after a while it came back to Iran with a bit change in it. For Islamic culture penetrated in to Europe, this instrument was used in some parts with different names , for example in Italy it was called "Lotto", in France "Loth" in Portugal "Aland"  and in Spain "Loud".