I observed prayer along with the Messenger of Allah ﷺ and with Abu Bakr, Umar and Uthman (may Allah be pleased with all of them), but I never heard any one of them reciting Bismillah-ir-Rahman-ir-Rahim loudly.  

صَلَّيْتُ مَعَ رَسُولِ اللَّهِ ﷺ وَأَبِي بَكْرٍ وَعُمَرَ وَعُثْمَانَ فَلَمْ أَسْمَعْ أَحَدًا مِنْهُمْ يَقْرَأُ {بِسْمِ اللَّهِ الرَّحْمَنِ الرَّحِيمِ}  

"I prayed behind the Messenger of Allah ﷺ, Abu Bakr, Umar and Uthman, may Allah be pleased with them, and I did not hear any of them say out loud: In the Name of Allah, The Most Gracious, The Most Merciful."  

صَلَّيْتُ خَلْفَ رَسُولِ اللَّهِ ﷺ وَأَبِي بَكْرٍ وَعُمَرَ وَعُثْمَانَ ؓ فَلَمْ أَسْمَعْ أَحَدًا مِنْهُمْ يَجْهَرُ بِ { بِسْمِ اللَّهِ الرَّحْمَنِ الرَّحِيمِ }  

[Machine] I prayed with the Messenger of Allah ﷺ , Abu Bakr, and Umar, and they did not recite aloud "Bismillah ir-Rahman ir-Rahim" (In the name of Allah, the Most Gracious, the Most Merciful) [Al-Fatihah 1].  

صَلَّيْتُ مَعَ رَسُولِ اللهِ ﷺ وَمَعَ أَبِي بَكْرٍ وَمَعَ عُمَرَ فَلَمْ يَجْهَرُوا بِ {بِسْمِ اللهِ الرَّحْمَنِ الرَّحِيمِ} [الفاتحة 1]  

I observed prayer along with the Messenger of Allah ﷺ and with Abu Bakr, Umar and Uthman (may Allah be pleased with all of them), but I never heard any one of them reciting Bismillah-ir-Rahman-ir-Rahim loudly. (Using translation from Muslim 399a)  

صَلَّيْتُ مَعَ رَسُولِ اللهِ ﷺ وَأَبِي بَكْرٍ وَعُمَرَ وَعُثْمَانَ فَلَمْ أَسْمَعْ أَحَدًا مِنْهُمْ يَقُولُ {بِسْمِ اللهِ الرَّحْمَنِ الرَّحِيمِ} [الفاتحة 1]  

[Machine] "I prayed behind the Messenger of Allah ﷺ , as well as behind Abu Bakr, Umar, and Uthman, and they would not audibly recite 'In the name of Allah, the Most Gracious, the Most Merciful' (Bismillah Ar-Rahman Ar-Raheem) in Surah Al-Fatiha."  

صَلَّيْتُ خَلْفَ رَسُولِ اللهِ ﷺ وَخَلْفَ أَبِي بَكْرٍ وَعُمَرَ وَعُثْمَانَ فَكَانُوا لَا يَجْهَرُونَ بِ {بِسْمِ اللهِ الرَّحْمَنِ الرَّحِيمِ} [الفاتحة 1]  

[Machine] "I prayed behind the Messenger of Allah ﷺ , and behind Abu Bakr, Umar, and Uthman. They would not recite aloud the Bismillahir Rahmanir Rahim (In the name of Allah, the Most Gracious, the Most Merciful) in Al-Fatiha (Chapter 1)."  

صَلَّيْتُ خَلْفَ رَسُولِ اللهِ ﷺ وَخَلْفَ أَبِي بَكْرٍ وَعُمَرَ وَعُثْمَانَ فَكَانُوا لَا يَجْهَرُونَ بِ {بِسْمِ اللهِ الرَّحْمَنِ الرَّحِيمِ} [الفاتحة 1]  

"I prayed behind the Messenger of Allah ﷺ, Abu Bakr, Umar and Uthman, may Allah be pleased with them, and I did not hear any of them say out loud: In the Name of Allah, The Most Gracious, The Most Merciful." (Using translation from Nasāʾī 907)  

«صَلَّيْتُ خَلْفَ رَسُولِ اللَّهِ ﷺ وَأَبِي بَكْرٍ وَعُمَرَ وَعُثْمَانَ رِضْوَانُ اللَّهِ عَلَيْهِمْ فَلَمْ أَسْمَعْ أَحَدًا يَجْهَرْ بِبِسْمِ اللَّهِ الرَّحْمَنِ الرَّحِيمِ»  

[Machine] "And the Messenger of Allah ﷺ , Abu Bakr, and Umar, may Allah be pleased with them, did not utter aloud 'In the name of Allah, the Most Gracious, the Most Merciful.'"  

«وَكَانَ رَسُولِ اللَّهِ ﷺ وَأَبُو بَكْرٍ وَعُمَرُ رِضْوَانُ اللَّهِ عَلَيْهِمَا لَا يَجْهَرُونَ بِ {بِسْمِ اللَّهِ الرَّحْمَنِ الرَّحِيمِ} »  

"I prayed behind the Messenger of Allah ﷺ, Abu Bakr, Umar and Uthman, may Allah be pleased with them, and I did not hear any of them say out loud: In the Name of Allah, The Most Gracious, The Most Merciful." (Using translation from Nasāʾī 907)  

«صَلَّيْتُ خَلْفَ رَسُولِ اللهِ ﷺ وَأَبِي بَكْرٍ وَعُمَرَ وَعُثْمَانَ فَلَمْ أَسْمَعْ أَحَدًا مِنْهُمْ يَجْهَرُ بِبِسْمِ اللهِ الرَّحْمَنِ الرَّحِيمِ»  

[Machine] I prayed behind Umar ibn al-Khattab, and he recited aloud "In the name of Allah, the Most Gracious, the Most Merciful."  

صَلَّيْتُ خَلْفَ عُمَرَ بْنِ الْخَطَّابِ فَجَهَرَ بِبِسْمِ اللهِ الرَّحْمَنِ الرَّحِيمِ