soundeffect in npc

[RagnarokOnline2015]

prontera,147,195,4 script Skill 4_M_SURA,{
soundeffect("555.wav", 0);
mes "You learned all skills!";
next;
atcommand "@allskill";
atcommand "@effect 909";
close;
}

Where is my mistake ? added sound GRF 

Please help me! Thank you!

 

[Asheraf]

if you're using a custom sound file make sure that the file is on PCM format.