Answered by Ustadh Tabraze Azam
Question: I have a few questions concerning regarding reciting silently in prayer.
1. Must the person offering salah be absolutely silent during these rakat? If not, what is the threshold between reciting silently and out-loud?
2. Should the person offering salah still say the Takbir out-loud when moving from one posture to the next?
3. Are there any/other elements of the salah that should be said out loud during those silent rakat?
4. As a request, would you be so kind as to offer some citations that I may read and increase my own understanding Inshallah.
Answer: Wa alaikum assalam wa rahmatullahi wa barakatuh,
I pray that you are in the best of health and faith, insha’Allah.
First of all, reciting ‘silently’ actually means ‘quietly’ with regards to the prayer.
 The minimum threshold for reciting as such is that one’s tongue and lips move, even if no sound is produced. The same applies to all invocations and supplications within the prayer.
 One would only say the takbir aloud if one was leading a congregation. Otherwise, one would also say this quietly.
Please consider: [a] reading The Absolute Essentials of Islam: A Basic Hanafi Manual of Faith, Prayer, and the Path of Salvation [b] and taking this: Absolute Essentials of Islam: Beliefs & Worship
And Allah alone gives success.
Checked & Approved by Faraz Rabbani