Loudspeakers were invented in the early 1900s, and they were introduced in
mosques in the 1930s, where they are used for the
adhan [["call to prayer"),
[1] and sometimes for khutbah [[sermons).
Outdoor loudspeakers, usually mounted on tall
minarets, are used five times a day for the call to prayer, sometimes starting as early as
4 a.m. Some mosques have loudspeakers that are powerful enough to be
heard as far as 5 km [[3 mi) away.
[2] In areas where more than one mosque is present, the loudspeaker sounds overlap one another,
[3] especially in the
early morning when sounds are more clearly heard. Loudspeakers are sometimes also used inside mosques to deliver sermons or for prayer.