If you are having trouble with your voice chat, here's some things to try.
There are two known causes of this.
Patch 1.63 fails to ask for Mic permissions correctly.
Previous versions of Killer Queen Black had a bug where after an update, OS level permissions to access the microphone got cleared . In this scenario, your mic is working fine in other games and applications, just not Killer Queen Black.
Here's a step by step guide to resolving this issue. Not for the faint of heart! Proceed with caution.
Method 1: Add Permissions to info.plist
Info.plistin a text editor (this could be tricky if you don't have one, google for "Sublime Text" and try editing using this app)
<key>NSMicrophoneUsageDescription</key> <string>Voice chat</string>
Next time you open Killer Queen Black and attempt to voice chat you should see a pop-up from Mac OS asking for for permission to grant Killer Queen Black microphone access. Make sure to allow!
Method 2: Disable System Integrity Check (Reboot Into Recovery Mode)
Reboot back into normal mode.
Perform Terminal Incantations
sudo sqlite3 ~/Library/Application\ Support/com.apple.TCC/TCC.db "INSERT or REPLACE INTO access VALUES('kTCCServiceMicrophone','com.Company.ProductName',0,1,1,NULL,NULL,NULL,'UNUSED',NULL,0,1551892126);"
/usr/libexec/PlistBuddy -c "Add NSMicrophoneUsageDescription string" ~/Library/Application\ Support/Steam/SteamApps/common/Killer\ Queen\ Black/Killer\ Queen\ Black.app/Contents/Info.plist
/usr/libexec/PlistBuddy -c "Set :NSMicrophoneUsageDescription Using voice chat" ~/Library/Application\ Support/Steam/SteamApps/common/Killer\ Queen\ Black/Killer\ Queen\ Black.app/Contents/Info.plist
Re-enable System Integrity Check (Reboot Into Recovery Mode)
Reboot back into normal OS mode.
You should now be all set!