Should someone leading a person praying 'Isha' (the night prayer) during the Shafa' and Witr (even and odd rak'ahs) prayers recite aloud or silently?

One should recite aloud in the even and odd (rak'ahs) if someone is following you in prayer, so that the follower may hear. This is also because reciting aloud is preferable in night prayers, and it is recommended to recite aloud in supererogatory night prayers and silently in supererogatory day prayers. However, if one recites aloud in their supererogatory day prayer, that is permissible.