I'll try.

Your tongue plays a big part in the process. Like say when growling (the proper way, not with your throat) try to create a higher pitch using your voice. Because when you growl, it's mainly just a deep exhaul magified with you voice. If you manipulate your voice into like say a scream, it combines with your growl. That's the best way I can put it. I found out how to do it while singing Dead By Dawn by Deicide, so it just came to me.

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