I have this same issue with only my own voice commands working.
Think it started last patch and I couldn't find out what it was.
Tested it again now with the new patch, and it worked just fine with the basegame before I installed the modpack. After installing the 0.9.8 modversion I can no longer hear the voice commands of allies/teammates, only my own.
I don't change anything with the sound.
Only mods I use are scoretimer, shottimer, secondary range and calm waves.