Glitch in I am

I have wondered about this "glitch" from the first time I listened to the song. It doesn't wreck the song for me by a long shot, but it is a sudden/abrupt sound which to me at first made me question whether my computer had goofed up in ripping the album from the CD.

Eventually I came to terms with the fact that the sound was just in there as an overlapping of vocals and it wasn't all that jarring.