Answered by Shaykh Amjad Rasheed
Is a woman’s voice considered `awra (nakedness) in our school? Is it permissible for her to recite the Koran in front of men who are not her mahram?
The voice of a woman is not considered `awra, so it is permissible to listen to her voice as long as fitna is not feared by it, for then it becomes haram. As for her raising her voice to recite the Koran in the presence of men who are not her mahram, it is not haram according to Imam al-Ramli, but it is disliked out of fear of fitna. Al Khatib al-Shirbini disagreed with him and said, “It is haram, by analogy that it is haram for a woman to raise her voice to call the adhan (call to prayer) in front of non-mahram men, as he expounded in Bushra al-Karim ( 1/76, 60). So for this reason, it is surely better for a woman to lower her voice in front of non-mahram men when she is reciting Koran so that she does not enter into difference of opinions.
Amjad Rasheed
[Translated by Sr. Shazia Ahmad]