What is the ruling on welcoming Ramadan or bidding it farewell with microphones in the form of individual chants from the mosque's loudspeaker?

It is legislated for a Muslim to rejoice and be glad at the advent of Ramadan, and to welcome it with sincere repentance and preparation for worship. They should bid it farewell by striving in acts of worship such as prayer, reciting the Qur'an, remembrance of Allah, supplication, i'tikaf (spiritual retreat), and seeking forgiveness, following the example of the Prophet (peace be upon him) who used to gladden his companions with the arrival of Ramadan and the good that accompanies it. As for welcoming its arrival and bidding it farewell in a specific manner, there is no basis for it in the Sharia.