I have a soundcard (Audigy) and regular speakers. It wasn't a voice, it sounded kind of like that beep when you hold down a bunch of keys at once (now that I check, it doesn't do that on my computer running Windows XP, but it does on my old Win95 and my school's Win98 computers). It happens when I click "Next" after selecting "Dump the Image of a CDROM". It also does it on "Next" after the second screen (drive select) when i click "Get CD Information/ Control Tray". It is definitely coming from my tower though, because it does it with my speakers off too. I don't really mind though, because I don't think I will ever use BlindWrite that much.
EDIT: This is in the Reading part of BlindWrite, I haven't done anything yet with the writing part.