A simple Push-to-talk to Open Mic converter. It will press the hardcoded key 'c' when you speak in the microphone.
I've found that open mic works best for me, and some games do not have the "open microphone" option!
Took an already working microphone level meter code sample from Stack Overflow and added my own functionality. Original source can be found here:
https://stackoverflow.com/questions/26574326/how-to-calculate-the-level-amplitude-db-of-audio-signal-in-java/26576548
Plans for the future: Actually understand how TargetDataLine works and how to calculate volume. Then make a nice UI for this little app and add the functionality to change the key as will.