Are the following prayers performed audibly or silently: the voluntary prayer after Maghrib, the third rak'ah of Witr prayer if performed like Maghrib prayer, Qiyam al-Layl, Raghibat al-Fajr (the two rak'ahs before Fajr), and Duha prayer?

A worshiper may whisper during supererogatory prayers during the day. For night prayers, one has the choice between vocalizing and whispering, with vocalizing being preferable unless whispering leads to greater devotion (khushu') or if vocalizing would disturb someone.

The Sunnah for night prayers is vocalization, as it fosters greater devotion in the heart and benefits listeners, unless there are sick people or those sleeping nearby, in which case one should lower their voice. There is no harm in whispering sometimes.

The Prophet, peace and blessings be upon him, forbade performing the Witr prayer in the same manner as the Maghrib prayer. It is permissible to perform Witr with three rak'ahs in two ways: either by making a salutation (taslim) between the even-numbered (shaf') and the odd-numbered (witr) rak'ahs, or by performing the three rak'ahs with a single tashahhud at the end.