Phone [Q] Xperia P Bootsound HELP

Hello, I have tried everything I could to enable custom bootsound on my Xperia P, but maybe someone will help me here with my specific problem. I have my phone rooted, and changed bootanimation on Watchdogs but I want to add sound to it . I tried add file like .mp3 and .ogg into /system/media or into /data/local and name them android_audio, bootsnd, bootsound, poweron, but nothings seem to work. And I tried add line in to desc.exe (s *nameofsound*.mp3/.ogg). Still no sound. Do have somebody experience with this ? Or maybe Xperia P doesnt support bootsound ? I have stock ROM, android 4.1.2. Thanks for any respond.

EDIT: And I downloaded, and launched Terminal and wrote this :
cd sdcard

still no sound