Some of the ma'mum (those praying behind the imam) raise their voices so that the person next to them can hear them during the recitation, the tasbih, and the tashahhud, which causes the person next to them to follow along and be disturbed.

The questioner : This listener from the Eastern Region, Abdul Wahhab Khalid from King Faisal University in Al-Ahsa, says: Some of the ma'mum raise their voices so that the person next to them can hear them during the recitation, the tasbih, and the tashahhud, which causes the person next to them to follow along and be disturbed. What is the ruling on this? May you be rewarded.

The Shaykh : The ruling in this matter is that it is not permissible for a ma'mum to raise his voice in a way that disturbs the other worshippers with him. This is because the Prophet (peace and blessings be upon him) said to his Companions one day, after hearing them recite loudly while each was praying for himself but reciting aloud: He said to them (peace and blessings be upon him) In another hadith, he said: It is well known that harming a Muslim is forbidden. Therefore, it is not permissible for a ma'mum to recite loudly, or to say the tasbih, takbir, or du'a in a way that disturbs his brothers. Yes, the imam should sometimes, in the prayers where recitation is silent, make the verse audible to the ma'mum, as established in the two Sahihs from the hadith of Abu Qatadah (may Allah be pleased with him), that the Prophet (peace and blessings be upon him) would sometimes make the verse audible to them. As for anyone other than the imam, it is not allowed.
So my advice to my Muslim brothers who disturb others with their recitation, tasbih, du'a, or tashahhud is to leave this matter, because they are conversing with Allah (Mighty and Majestic), and Allah (Glorified and Exalted is He) knows the secret and what is hidden.