The ruling on conveying the takbirat and other things on behalf of the imam

Question:
The brother I. S. A. from Chicago in America says in his question: I performed 'Umrah some time ago, and I noticed in the Sacred Precinct during the prayer that one of the brothers, and I think he was the mu'adhdhin, was repeating the takbir after the imam. I found that strange. After the prayer, I asked one of the brothers, and I think he was from Makkah al-Mukarramah, about it. He said: This is called tabligh, meaning conveying the takbir to the ma'mums who may not hear the imam's voice clearly. I said to him: But the ma'mums hear him through the loudspeakers spread throughout the Sacred Precinct. He said: It is an old custom that existed before the loudspeakers and then continued. In fact, his words are not convincing.
Your Eminence, the Shaykh: What is the ruling in the Shari'ah regarding this tabligh, which causes much disturbance to the worshippers, given that these loudspeakers transmit the imam's voice to all parts of the Sacred Precinct and all the ma'mums hear it clearly? Also, there are sensitive and precise microphones that are easily attached to the imam's pocket to be with him in his ruku', sujud, and all his movements. We ask you to clarify the truth in this matter. May Allah prolong your life in obedience to Him?

Answer:
I do not know of any harm in tabligh; because there may be people at the edges of the Sacred Precinct who do not hear the imam's voice. It is established from the Prophet (peace and blessings be upon him) that when he prayed with the people during his final illness, Abu Bakr al-Siddiq (may Allah be pleased with him) was conveying it on his behalf. May Allah grant success.