Assalamualaikum ustaz. How are you? May ustaz always be in the best of health. I have a question. What is the ruling of speaking loudly during a funeral procession? Is it permissible? We are encouraged to ponder upon and remember death during the funeral procession, aren’t we? Hope for an explanation from ustaz.
It is makruh to speak loudly during the funeral procession. Especially on worldly matters. That moment shall be used to ponder upon death, barzakh and ponder upon the remainder of age we still have. This is because, sooner or later, we will also face the same thing. May Allah bless us with a beautiful ending.
Funeral procession is among the sunnah which is highly encouraged to be done. This is based on a hadith narrated by al-Bara’ bin ‘Azib. He said:
أَمَرَنَا رَسُولُ اللَّهِ صلى الله عليه وسلم بِسَبْعٍ وَنَهَانَا عَنْ سَبْعٍ أَمَرَنَا بِاتِّبَاعِ الْجَنَازَةِ وَعِيَادَةِ الْمَرِيضِ وَتَشْمِيتِ الْعَاطِسِ وَإِجَابَةِ الدَّاعِي وَنَصْرِ الْمَظْلُومِ وَإِبْرَارِ الْقَسَمِ وَرَدِّ السَّلاَمِ
The Messenger of Allah (ﷺ) ordered us with seven things and he forbade us from seven. He ordered us to follow the funeral procession, visit the ill, reply to the sneezing person, accept the invitation, assist the oppressed, help the one who made an oath and return the Salam. 
A funeral procession is something that is able to remind us of death. However, there are some ethics to be followed. Among the ethics are being silent during the whole funeral procession. Al-Khatib al-Syarbini quoted the statement of Imam al-Nawawi. He said:
قَالَ فِي الْمَجْمُوعِ: وَالْمُخْتَارُ بَلْ الصَّوَابُ مَا كَانَ عَلَيْهِ السَّلَفُ مِنْ السُّكُوتِ فِي حَالِ السَّيْرِ مَعَ الْجِنَازَةِ، وَلَا يَرْفَعُ صَوْتَهُ بِقِرَاءَةٍ وَلَا ذِكْرٍ وَلَا غَيْرِهِمَا، بَلْ يَشْتَغِلُ بِالتَّفَكُّرِ فِي الْمَوْتِ وَمَا يَتَعَلَّقُ بِهِ
Imam al-Nawawi mentioned in the book al-Majmu’: The chosen and the most accurate opinion is what is done by the salaf which is being silent during the whole funeral procession. One shall not raise his voice with the recitation of al-Quran, dhikr and etc. In fact, he shall make himself busy with pondering upon death and anything related to it. 
The dalil for this statement of Imam al-Nawawi is the narration of Qays bin ‘Ubad RA, where he said:
كان أصحابُ رسولِ اللَّهِ صلى الله عليه وسلم يَكرَهونَ رَفعَ الصَوتِ عِندَ الجَنائزِ وعِندَ القِتالِ وعِندَ الذَكرِ
The companions of the Prophet PBUH dislike raising their voice while being beside the janazah, during the war and during dhikr. 
Besides, it is makruh to speak on worldly matters during the funeral procession. The moment shall be used to ponder upon and think about death. This is explained by Imam al-Nawawi He said:
وَيُكْرَهُ اللَّغَطُ فِي الْمَشْيِ مَعَهَا، وَالْحَدِيثُ فِي أُمُورِ الدُّنْيَا، بَلِ الْمُسْتَحَبُّ الْفِكْرُ فِي الْمَوْتِ وَمَا بَعْدَهُ وَفَنَاءِ الدُّنْيَا وَنَحْوِ ذَلِكَ
It is makruh to raise one’s voice during the funeral procession. The same goes for speaking on worldly matters. In fact, it is sunnah to think about death, what happens afterwards, the doom of this world and etc. 
Ibn Hajar al-Haitami also states that it is makruh to speak loudly during the funeral procession. It is also mentioned as al-laghat. This also includes dhikr or reciting al-Quran loudly. 
Hence, it is makruh to speak loudly during the funeral procession. Especially speaking on worldly matters. That moment shall be used to ponder upon death, barzakh and ponder upon the remainder of age we still have. This is because, sooner or later, we will also face the same thing.
 Riwayat Al-Tirmizi, no 2809, Jami’ Al-Tirmizi (1998), Dar Al-Gharb Al-Islami,Beirut, j.4 h.414
 Al-Syarbini, Muhammad Bin Ahmad, Mughi Al-Muhtaj ila Ma’rifah Ma’ani Alfaz Al-Minhaj(1994), Dar Al-Kutub Al-‘Ilmiyah, Beirut, j.2 h.48
 Riwayat Al-Baihaqi no 7262, Al-Sunan Al-Kubra(2011), Markaz Hijr Li Al-Buhuth wa Al-Dirasat Al-‘Arabiyah Al-Islamiyah, j.7 h.510.
 Al-Nawawi, Yahya Bin Syarf, Raudhah Al-Talibin wa ‘Umdah Al-Muftin (1991), Al-Maktab Al-Islamiy, Damsyik, j.2 h.116.
 Ibn Hajar Al-Haitami, Ahmad Bin Muhammad, Tuhfah Al-Muhtaj fi Syarh Al-Minhaj (1983), Dar Ihya’ Al-Turath Al-Arabiy, Beirut, j.3 h.187.