Does one prostrate for forgetfulness if one recites quietly in a loud prayer, or must one repeat the prayer?

Question:
I am often forgetful, and in some of the loud prayers I forget and recite quietly, then I remember and recite aloud, and I prostrate for forgetfulness. Do I have to repeat the prayer? Or how should the matter be handled? Is my action valid? May Allah reward you with good.

Answer:
Reciting aloud and reciting quietly are both a recommended practice (sunnah). So if one recites aloud in a place where one should recite quietly, or recites quietly in a place where one should recite aloud, there is no harm; his prayer is valid, and he has only missed a recommended practice. If he forgets and recites quietly in a place where he should recite aloud, and then remembers, he should recite aloud the remainder of the recitation. Likewise, the reverse: if he recites aloud in a quiet prayer while forgetting, and then remembers, he should recite quietly and complete his recitation. It is not obligatory for him to prostrate for forgetfulness, and if he prostrates as a recommended practice, there is no harm, and his prayer is valid. May Allah reward you with good, and may Allah reward you.