These Guides will show you how to configure and use the whisper feature on Mumble.
Video Guide
Written Guide
Follow these Steps:
1. Click on Configure mumble and then click on “Settings.”
2. Click on Shortcuts.”
3. Click Add.”
4. Click on Unassigned” and then select”Whisper/Shout”from the drop down list.
5. Click on the 
Button, then click on the Drop Down Menu and Select the person you wish to whisper to.
6. Select what keyboard shortcut or mouse button you want to use.
7. Click OK.”
If you have any questions about Mumble, please ask here on the forums or mumble.