The word "muezzin" refers to a person in Islamic culture who calls Muslims to prayer from a mosque. They use a special chanting voice and loudspeakers to make the call. Full definition
To this end, the Pope is «not averse to giving hints» that he himself «might... in the year 2000 announce his acceptance of the Qur» an and summon the faithful, through the papal muezzin, to join him in prayer at the Mosque of St. Peter.» (firstthings.com)
Then I heard the two strange sounds I still associate with evenings in Igbaja: first, fruit bats pinging in the dense mango trees overhead, and then, from the big mosque in the center of town, the distorted hiss and crackle of the recorded muezzin, calling the Muslim faithful to evening prayer and» I couldn't help thinking» if necessary, to holy war. (firstthings.com)