It is well-established in the Sunnah

Q 1: Is it permissible for the Imam (the one who leads congregational Prayer) to go up onto the Minbar (pulpit) with a microphone to talk into?

A: It is permissible to help his voice reach as many people as possible. (Part No. 8; Page No. 251) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.