I believe I know what you mean of that sound, it does happen' to me when I make my own track, and it might be just a minar glitch or bug, but I've never seen one getting very loud or for any long time period continuing.
Idk if this link shall help yah, but I hope so, if you need anything else, please send me a private message and I will get back to you A. S. A. P.
Good luck! ^.^
http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=13024.0 (http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=13024.0)
Hmm, try this method~
1. Download any music you like, ANY.
2. Name it.
Ex. Pop.
3. Go to Main Disk >> C: > FeralHeart and open music.cfg in notepad.
4. Then you'll see all the plain music and stuff.
Make a new one as named this.
Ex. [MyMusic]
5. And write this.
Ex. media/music/Pop.mp3
6. Exit it and open up the game.
Then go to 'Tools' >> Map Maker > You're created map and you'll see something write in the 'Music (Group or Filename):
7. Then write this.
Ex. MyMusic.
8. Then press 'Test' and you'll hear the music you created.
You may have as many music filenames in the MyMusic group as you like.
Good luck! ^.^