Windows Media Player had background noise but no voices

For high-quality video files (multiple audio channels), WMP playback has background noise and music, but no voices. In VLC (which had the same issue) I corrected the problem by changing output from "original" to "stereo". I can find no similar configuration in WMP - but I need WMP to run another 3rd party program. Any help with this WMP configuration issue greatly appreciated. Thanks. Peter