A mu'addhin (/muːˈɛzɪn/; Turkish: müezzin from Arabic: مؤذن, muʾaḏḏin IPA: [muʔaðːɪn]) is the person appointed at a mosque to lead and recite the call to prayer for every event of prayer and worship in the mosque. The mu'addhin's post is an important one, and the community depends on him for an accurate prayer schedule.
The professional mu'addhin is chosen for his good character, voice and skills to serve at the mosque. However, the mu'addhin is not considered a cleric, but in a position comparable to a Christian verger. When calling to prayer, the mu'addhin faces the qiblah, the direction of the Ka'bah in Makkah, while reciting the adhan.
The call of the mu'addhin is considered an art form, reflected in the melodious chanting of the adhan. In Turkey, there is an annual competition to find the country's best mu'addhin.
Historically, a mu'addhin would have recited the call to prayer atop the minarets in order to be heard by those around the mosque. Now, mosques often have loudspeakers mounted on the top of the minaret and the mu'addhin will use a microphone, or the mu'addhin recording is played, allowing the call to prayer to be heard at great distances without climbing the minaret.