7 Days to Die volume changes causes my voice chat volume to also change, how do I fix this?

Issue

When I am running a voice chat (Hangouts or Skype) with friends, as soon as I start 7 Days to Die the voice chat volume (what I hear) gets quiet.

Attempted Solution

I up'ed my speaker volume (causing the game volume to also rise) this allowed me to hear the voice chat again. However doing this also made the game too loud. However when I turn down the game volume it also turns down the voice chat volume.

I think the problem is...

The game volume is somehow linked to my chat volume and I can't define separate values for each.

Bubblegum and Paperclip Fix

I am now running Hangouts on my Phone until we upgrade the server to the next patch and hope it is fixed (I am currently on A11).

I would be happy if anyone had a better solution or some suggestions on a fix.

Update 1

Thank you for the help so far, I haven't found a good solution yet but we are upgrading the server and should know if its fixed with the newest release.

Update 2

Again thank you for the suggestions everyone, I follow the advice in the answer (and some of the comments) and it did not work until I upgraded to Alpha 12. It is now working as everyone describes. Up-votes for everyone once for helping me find the solution (once I have the rep to upvote)

Upgrading to Alpha 12.4 from Alpha 11.6 did the trick!