Allah tells us to be quiet and to listen when the Qur'an is recited. So one should not speak in the mosque. One should not speak even in a whispering tone. The Mosques are not places to speak. When the Qur'an is recited, it should be listened to quietly. I see this almost in a great portion of all mosques. And that –people speaking in a high tone while the Qur'an is recited- is also sign of the Last Day and the portent of the appearance of Mahdi (pbuh). - Harun Yahya