Chiascript

I have noticed that although I have good sound with Express Scribe, I have even better sound when using other players, such as Windows Media Player, or KMP player for instance. With Express Scribe, I can hear the speaker but the end of his/or her sentences are distroted. I cannot hear clearly or some words in the sentences they are speaking are a bit distorted. (and Im not deaf yet ) I would like to know if maybe this is an issue with my sound card? Perhaps I need a better on than the one that is on the motherboard Realtek AC? Any suggestions? I live in Greece so some sound cards may not be available easily, if this is the problem that is. I would like to continue to use Express Scribe and not the other players, as it is much easier to use and much faster with the short keys.