Adhan
The adhān (Arabic: أَذَان) or the azān (Persian: اذان) is the Islamic call to prayer. The muezzin reads it out aloud. The root of the word is ʼḏn "to permit", and another derivative of this word is uḏun, meaning "ear."
The muezzin reads Adhan in the mosque, sometimes from a minaret. He usually does this five times a day. Adhan is used to call other Muslims to do the prayers. There is a second call, known as iqama (set up) that is used to tell Muslims to line up for the start of the prayers. Sometimes, loudspeakers are used on the minarets.
Sunni and Shi'a use versions of adhan which are slightly different from each other.
Adhan Media
The announcer of the Adhan is called a "Muezzin" (miniature depicting Bilal ibn Rabah the first Muezzin).
The Muslim call to prayer, is known as the "Adhan".
Sunni adhan in Matey Qoqanuly mosque, Kazakhstan
photo of kalima at Bab al-Nasr of Shia Fatimid dynasty of Cairo with phrase ʿalīyun walīyu -llāh
The qiblah of Mustansir of Shia Fatimid dynasty of, in Mosque of Ibn Tulun of Cairo showing Kalimat ash-shahādah with the phrase ʿalīyun walīyu -llāh