Before the minaret became a standard feature of mosque architecture, the earliest muezzins are said to have called the adhan from the highest rooftop available, and the tower form developed over the following centuries partly to project the call further across a growing city, becoming one of the most recognisable features of Islamic architecture in the process.
Amplification changed the office considerably in the twentieth century: loudspeakers now carry the call across distances no human voice could reach unaided, and in a number of countries, including Turkey and several Gulf states, a single centrally coordinated recording is broadcast from many mosques at once rather than each mosque employing its own muezzin, a shift that has reduced the number of working muezzins even as the call itself is heard more widely than ever. Noise regulations affecting the volume and timing of the amplified call have become a live civic issue in some cities with mixed populations.
Women have served as muezzins in a small number of mosques, including women-led congregations and a few mixed mosques in recent decades, but the practice remains a minority position contested by most schools of Sunni jurisprudence, which restrict the public call to prayer to men.