What is the ruling on using loudspeakers in prayer for the Imam and the congregants?

Using loudspeakers in the mosque for the Adhan (call to prayer), Iqamah (call to commence prayer), and the prayer itself is permissible. In fact, it may even be required to achieve certain religiously intended goals, such as raising the voice for the Adhan, reminding people about the prayer, and enabling listening to the recitation and Takbir (pronouncement of "Allahu Akbar"). However, care must be taken not to disturb other mosques, in accordance with the Prophet's (peace be upon him) saying: "And let not some of you raise their voices over others in recitation during prayer." As for the worshipper praying behind the Imam, it is not prescribed for him to raise his voice in recitation unless he is acting as a voice amplifier for the Imam.