You should play with the settings in your sound plugin in ePSXe, or use a different plugin altogether. One that I've never had trouble with (and has always produced the most accurate sound) is EternalSPU. You can get any plugin at <a href="http://www.ngemu.com">NGEmu</a>.

As for getting data ove to your computer from your memory card, you'd need to buy an adapter, as far as I know. I don't think there's a way to get the data via USB or anything like that.