Must the worshipper hear their own recitation during prayer?
Chapter on the Description of Prayer
Al-Mughni
Book of Prayer
Primary text
The worshipper, whether leading the prayer (Imam) or praying alone, must hear themselves recite the obligatory phrases. This is because the Takbir is an utterance spoken by the tongue, and speech requires sound, which must be audible. Since the closest listener is the person speaking, not hearing it means the saying of the statement is not confirmed. This ruling applies equally to men and women.
Supporting text
If the worshipper has an impediment, such as deafness (tarash), or another hindrance preventing hearing, they must recite it at a volume such that, were the impediment absent, they would hear themselves.