Extreme sound problem

[JigoKuu]

Hi!

I am really beginner in these emulator-things (and everything related to gaming, lol *noob* so please be patient with me!!), and I have a really irritating problem. I was able to start playing with the game called God Eater Burst with PSP emulator. Everything was fine, but when a kind of prologue started, the sound started to falter (I hope this is the right word :,D), too. The picture lagged a bit, too, but the sound is even worse! And I do not know why... the kind of promo video was so perfect, both the graphics and sounds were all right.

I also do not know what to do, but because of it, I'm absolutely unable to enjoy the game :,< I tried to change the settings, but nothing good happened... (but the situation didn't become worse, so I'm glad) Could you help me to solve this problem, please?

(If it's needed, I can try to record the sound... it's so sloooooooow and rugged, ehh...)

Thank you in advance!:3
And sorry, I'm Hungarian and my English is full of mistakes, too ^^" But I hope I was able to explain my situation.