A muezzin performs the adhan, the call to prayer, from a mosque five times daily, traditionally from a minaret so the call could carry across a town or neighborhood to summon the faithful to prayer at its appointed time, a role historically requiring a strong, clear, far-carrying voice trained in the adhan's specific melodic and textual form, which varies somewhat between regions and schools of practice but follows a recognizably consistent core structure proclaiming God's greatness and the truth of Muhammad's prophethood. Bilal ibn Rabah, a companion of the Prophet Muhammad traditionally regarded as the first muezzin, chosen for the distinctive quality of his voice, remains a figure of particular reverence in the office's own historical memory, and his name is still frequently invoked in discussions of the muezzin's role and its origins.
The twentieth century's introduction of electronic loudspeakers transformed the practical reach and audibility of the call to prayer far beyond what an individual voice could achieve unamplified, a change that has occasionally prompted local noise-regulation disputes, particularly in religiously mixed or majority non-Muslim neighborhoods in various countries, over the appropriate volume and timing of amplified calls; in parallel, many mosques today use a recorded rather than a live call for at least some of the five daily prayers, a practical shift that has somewhat reduced the muezzin's traditional role even as the office continues in its live, unamplified or amplified form in a great many mosques worldwide.