[Japo]

Those sound like two separate issues. Do you get sound interference only when playing fullscreen or always? And what do you mean exactly by "interference"? Some scratching sound like in a radio, or just that the sound is choppy, not playing at times during a fraction of a second?

I don't think it's the first one since I haven't experienced it myself but if it's so for you let me know with more details. If the sound is choppy, just increase the cycles in DOSBox pressing Ctrl+F12 repeatedly, oddly enough this game is quite demanding in this regard. There's a limit to how many cycles your machine can emulate, to double it change the emulated core to "dynamic" mode --there's a number of other things you can do to decrease the cycles needed. It's also possible that the game works poorly because the cycles are too high instead of too low, if it gets worse every time you press Ctrl+F12, try decreasing cycles with Ctrl+F11 instead.

The picture quality is because DOSBox has to make an aspect correction if it's trying to display a 640x400 image in your Windows resolution. The obvious alternative is playing in a window.