Question Summary:
How loud does one have to recite the Quran in Salaah

Question Detail:

 
In salaah, whether on own or in a congregation is it allowed to recite inaudibly? (You don't hear yourself recite, but you move your tongue and recite inaudibly like that) is this allowed?
Also please add, if possible, the stance of reciting inaudibly of the four schools of thought, whether acceptable or not. 

Answer :

In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
1)     According to the Hanafi Mazhab, one should not recite the Quran behind the imam, whether it be loudly or silently.[1]
When praying individually, one is minimally required to recite in such a tone that he can understand himself.[2] 
2)     We issue rulings only according to the Hanafi Mazhab.
 
And Allah Ta’āla Knows Best
Muhammad Haris Siddiqui
Student Darul Iftaa
Melbourne, Australia
Checked and Approved by,
Mufti Ebrahim Desai.