ENOfficial
It was narrated that Abdullah bin Abi Qais said: "I asked Aishah: "How did the Messenger of Allah (ﷺ) recite at night- did he recite loudly or silently?" She said: 'He used to do both; sometimes he recited loudly and sometimes he recited silently.'"
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا شُعَيْبُ بْنُ يُوسُفَ، قَالَ حَدَّثَنَا عَبْدُ الرَّحْمَنِ، عَنْ مُعَاوِيَةَ بْنِ صَالِحٍ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي قَيْسٍ، قَالَ سَأَلْتُ عَائِشَةَ كَيْفَ كَانَتْ قِرَاءَةُ رَسُولِ اللَّهِ صلى الله عليه وسلم بِاللَّيْلِ يَجْهَرُ أَمْ يُسِرُّ قَالَتْ كُلُّ ذَلِكَ قَدْ كَانَ يَفْعَلُ رُبَّمَا جَهَرَ وَرُبَّمَا أَسَرَّ .
sunnah.com