While escorting the dead, the persons in the funeral procession should avoid talking and even raising their voices with dhikr. Silent reflection is very much required in such a situation. The Prophet’s Companions (may Allah be pleased with them all) considered it an undesirable act to raise one’s voice, even with dhikr, while escorting the dead

Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada., states the following: “As recorded in the works of Hadith, the Sunnah of the Prophet (peace and blessings be upon him) while escorting or accompanying the funeral procession is to observe silence. He (peace and blessings be upon him) is reported to have said, “Do not follow the dead by noise or fire.” The Companions of the Prophet, therefore, considered it undesirable or makruh to raise one’s voice with dhikr or du`a’ (supplication) while escorting the funeral.
If anyone wants to make dhikr, he should do so only silently. The wisdom for silence at this time is to reflect on death and destiny. Therefore, to chant dhikr loudly would only upset this wisdom.
In other words, in Islam there is a time for reading aloud and a time for remaining silent, and the funeral is a time for silent reflection or remembrance. In short, the Sunnah while accompanying the funeral is to silently reflect or remember Allah.”
Moreover, Sheikh `Atiyyah Saqr, former head of Al-Azhar Fatwa Committee, adds: “The opinion which is deemed to be the most correct and the one which was adopted by the righteous successors (may Allah be pleased with them all) is that one should remain silent while escorting the dead. One’s voice should not be raised in either Qur’anic recitation or dhikr or any other talk.
Ibn Al-Mundhir stated that the Prophet’s Companions (may Allah be pleased with them all) used not to raise their voices in three situations:
–While escorting the dead.
–When being involved in Allah’s Remembrance.
–When fighting their enemies.
Sa`eed Ibn Al-Muthayyeb, Sa`eed Ibn Jubair, Al-Hasan, An-Nakh`ie, Imam Ahmad, Ishaq stated that it is makruh (disliked) for the person escorting the dead to say, “Seek Allah’s Forgiveness.”
May Allah guide you to the straight path, and guide you to that which pleases Him, Amen.