MorphVOX Voice Changer Software can be used in any game or streaming software that takes a Windows microphone

Overwatch uses the default Windows microphone. To allow Overwatch to use the MorphVOX Microphone you will have to set the Windows Default microphone as explained here click here

MorphVOX sound tips:

1. Set the quality to highest by accessing MorphVOX Preferences menu under Sound Settings.
2. Reduce your real microphones level if you get distortion or feedback.
3. Map sound effects to hot keys:
   click here
4. Try other voice packs for more voices:
   click here