OK take a step back, I think you are laser focused on the digital output of your CD drive for no reason.
What games have no voices? Are they MPC based games with voices stored as CD audio tracks (like Jones in the Fast Lane CD Edition) or are the voices digital audio files? (Like Sierra CD games)
Are you able to play regular music CDs in the drive through the sound blaster card?
98/DOS Rig: BabyAT AladdinV, K6-2+/550, V3 2000, 128MB PC100, 20GB HDD, 128GB SD2IDE, SB Live!, SB16-SCSI, PicoGUS, WP32 McCake, iNFRA CD, ZIP100
XP Rig: Lian Li PC-10 ATX, Gigabyte X38-DQ6, Core2Duo E6850, ATi HD5870, 2GB DDR2, 2TB HDD, X-Fi XtremeGamer