Do you have a raid weapon or Murmur in your equipped at the time? I was doing some Patrol on the moon, sniping fallen ontop of the moon base and heard in a little girl's voice "I died...here." I dropped down into the base to check it out, to see if i was hearing things, nothing. I killed 2 dreg inside the base and around one of the computer stations i hear a loud whisper "HERE!" gave me the creeps.