http://bugs.winehq.org/show_bug.cgi?id=27883
--- Comment #6 from Andrew Eikum aeikum@codeweavers.com 2011-07-25 10:54:06 CDT --- Hmm, I actually have the opposite problem. The intro Bioware and EA animations have audio, as does the "Previously on Mass Effect" video, but the narration speech doesn't work. This is with both OSS and ALSA drivers, with dsound in either Full or Emulation mode. That all makes me think the bug is someplace in dsound, or an unexpected change in winmm that breaks dsound. Nothing obvious popped out of my log.
Cùran, what audio driver are you using? Could you attach a +tid,+mmdevapi,+winmm,+dsound,+alsa,+coreaudio,+oss log? They can get large pretty quick, so just get through the soundless intro videos and quit out.