REWARDS OF LOUD AND SILENT RECITATION
Hadhrat 'Uqbah ibn Aamir (Radhiyallaho anho) reports that Rasulullah (Sallallaho alaihe wasallam) said, "One reading the Qur'an loudly is like one who gives alms openly, and one who reads silently is like one who gives alms secretly." {Trmizi}
Sometimes it is more rewarding to give alms openly, when there is some good reason and the intention is to induce others by example. At other times, giving alms secretly is more virtuous, for instance, when the intention is to avoid show on one's own part or to save the recipient from humiliation.
In the same way, recitation of the Qur'an in a loud voice carries more reward when the intention is to induce others; besides, in this there is reward also for those who listen. At times it would be preferable to read silently, so as to avoid inconvenience to others or show on one's part. Thus the reading, either way, has independent virtue. Sometimes one mode is preferable, and sometimes the other.
Many people have argued on the basis of this hadith that reading in a low voice is more virtuous. Imam Baihaqi (Rahmatullah alaih) in his book, 'Kitabush Shu'ab', has written that Hadhrat 'Aa'ishah (Radhiyallaho anha) had reported that the reward of doing a good act secretly is seventy times more than that of doing it openly. But, according to the rules laid down by the muhadditheen (scholars of ahadith), this hadith is dha'eef (weak).
Hadhrat Jaabir (Radhiyallaho anho) reports that Rasulullah (Sallallaho alaihe wasallam) said, "Do not read in a loud voice, lest the voice of one should get mixed up with the other." Hadhrat Umar ibn Abdul Aziz (Radhiyallaho anho) found a person reading the Qur'an in a loud voice
in Musjid-i-Nabawi and had stopped him. The reader, however, tried to argue, whereupon Hadhrat 'Umar ibn Abdul Aziz (Radhiyallaho anho) said, "If you read for the sake of Allah, read in a low voice and, if you read for the sake of men, then such reading is of no use."
Similarly an advice of Rasulullah (Sallallaho alaihe wasallam), for reading the Qur'an in a loud voice, has also been reported.
'Sharhul Ihya' contains both 'riwaayaat' (Plural of 'riwayat- Narrative tradition) and 'aathaar' (sayings of Sahabah) urging the reading of the Glorious Qur'an in a loud as well as in a low voice.
Refrence;
Book Name: Virtues Of Quran.
Author Name: Shaikh ul Hadees Maulana Zikariya Sahab.