of Allah the Exalted, followed by an affirmation of His oneness and a denial of its opposite—associating partners with Him—then an affirmation of the messengership of Muhammad ﷺ, then a summons to prayer, the pillar of Islam; then a summons to prosperity, meaning triumph and everlasting bliss; and finally a reminder to establish the prayer.
Such lofty and majestic meanings are contained in the adhan and the iqama.
The adhan and the iqama are mandatory for men, for al-Bayhaqi (1/408)—though he judged the report weak—narrated from Asmaʾ bint Yazid that the Prophet ﷺ said, “Women have neither adhan nor iqama.”
A rigorously authentic, mawquf report from Ibn ʿUmar is likewise recorded by al-Bayhaqi (1/458), as Ibn al-Mulaqqin noted in Khulasat al-Badr (1/106).
Al-Wazir said: The scholars unanimously agree that the adhan and iqama are neither prescribed nor recommended for women, and—according to the sound view—they are obligatory whether one is resident or traveling, for the Prophet ﷺ never left them out in either circumstance.
Al-Nawawi stated: According to the majority of scholars, early and late, the adhan and the iqama are not legislated for any prayer other than the five obligatory ones.
Number of statements in the adhan: the preferred form consists of fifteen statements.
The Shaykh said: The methodology of the hadith scholars is to deem permissible every wording that is authentically transmitted from the Prophet ﷺ, and they do not disapprove of any of them.
Ruling on replacing the adhan with recordings:
Shaykh Muhammad ibn Ibrahim Al al-Shaykh said: We object to substituting the adhan with phonograph records, for that would open the door for people to trifle with the religion.
There is no harm, however, in using a voice amplifier during the adhan, the Friday sermon, the two ʿId sermons, and similar occasions, so that the adhan may be heard over long distances.
This is not an innovation, for an innovation (bidʿa) is a newly introduced practice in the religion devised to rival the Sharia. The microphone serves only to amplify the voice; it is simply a means of conveyance and therefore belongs to customary matters. Allah knows best.