I think I've found something! Those low frequency parts? They look like morse code too! You can tell because the waves are so small (that might not make sense but see the pictures for more info). For example, the one right at the end is this:
http://imgur.com/EAKeTtR
Which in turn can be interpreted as .-..
before that is this:
http://imgur.com/AqKUGUK
which can be interpreted as ..
I think this should be investigated further, by some one more able to interpret morse code.