Adan in Islam is required to inform people of the times of prayer and to show the rites of this religion.
Many divine texts from the Koran and the Sunna affirmed its legitimacy. Allah the Great said: «…When the call is made for prayer…». [surat Al-Jumu’ah / The Friday, form the verse 9].
The prophet- may peace be upon him- said:
«When the time of prayer is come, one of you should pronounce the Adhan and the oldest of you lead the prayer». [Agreed on].
«Indeed! Allah and His Angels pray for those who pray in the first row, and the sins of the one who calls to prayer are forgiven the extent of the raising of his voice and he has the same reward as those who pray with him». [Reported by El-Barâ’ bnu Azib].
«Whenever you are grazing cattle or in the wilderness and you want to pronounce Adhan for the prayer, raise your voice in doing so, for whoever hears it, whether a human being, a jinn or any other creature, will be a witness for you on the Day of Resurrection». [Reported by El-Boukhari from Abi Saîd El-Khodri].
Therefore taking into account these arguments like (…So raise your voice while pronouncing Adhan), it is allowed to use the loud speaker while pronouncing Adhan in a reasonable manner in order to realize its objective (to be heard by people and to inform them that the time of prayer has come).
