I can assist you here if still need be, I can send you a script that uses the Nircmdc.exe loop command.
I struggled recently to find a solutions for this problem, so took little bits of information from different sites and it works well. Just open it before the game or add it to windows startup. I'm not going to send you a file, as I would be weary of viruses or other bs stuff people send or hide in files online. I will type the command out here for you. Just create a batch file in notepad++ with this command:
nircmdc.exe loop 172800 500 setsysvolume 32768 default_record
The 32768 is the mic volume level, that is 50%, obviously double that number will be 100% etc.
I am not 100% sure if I had to install nircmdc.exe for when it actually started working, but either way, it works now. This is the link to the page where u can download that.
http://www.nirsoft.net/utils/nircmd.html
Let me know if it works for you.