i'm trying to decrypt audio files for signalis they are Bank files start with RIFF FEV FMT . 
here is the decryption key :   X3EK%Bbga-%Y9HZZ%gkc*C512*$$DhRxWTGgjUG@=rUD
when i try to use it on decrypted fsb it keep giving me audio without sound 
can someone please help 
sample : https://mega.nz/file/mwBj0Lpb#WJw94xWzI ... ieLXtKuGWQ
tool to remove nulls from file to get fsb from xetention : https://www.dropbox.com/s/43q7zmov01ru2 ... p.exe?dl=1
thread : https://forum.xentax.com/viewtopic.php?t=25948