There could be two reasons for this: A) You don't have a 16-bit/44.1 kHz audio card. 8-bit cards, such as the Soundblaster Pro, don't work. ReBirth is a 32-bit application with 16-bit audio output! B) Your card is not properly configured or installed - maybe you are using some kind of custom driver from the manufacturer. Some drivers are not 100% compatible with Windows 95, and consequently not with ReBirth. Perhaps you are using an old Windows 3.1 16-bit driver? Do all other audio applications play back sound properly?