It is narrated from Ata that Sayyiduna Abu Hurayrah (may Allah be pleased with him) said: There is recitation in every prayer. In the prayer in which the Messenger of Allah (peace and blessings be upon him) made us hear (that is, he recited aloud), we too made you hear, and in the prayer in which he concealed it from us (that is, he recited quietly), we too concealed it from you. Whoever recites Surah al-Fatihah, it will suffice for him, and whoever recites more, that is better.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2370