Commander Ludwig was a Starfleet officer in the 24th century. In 2373, she transmitted a message from her assignment, the USS Madison, during a fleet action facing a Borg cube which was moving towards Earth through the Typhon sector. (Star Trek: First Contact)
Commander Ludwig's voice was heard briefly in radio chatter and provided by an unknown actress.
It is unknown if she or her ship survived, only a few words of her message were even heard.