This card looks very similar to Heathkit's Heath Voice 2000 Card.

The Card says "P C Voice Card 85-3348-01" on the front
I think the only part that is obscured in the pictures is the little blue wheel on the top - that is the volume control.
It has 2 RCA jacks.

Does anyone have information on, drivers for, or know of any software that supports this card? Thanks!