You have probably experienced that your Chromebook´s system microphone or plugged in mic is not working with any Linux app? 

Regardless of the full integration of Linux App supported with¨linux Beta¨ flag on Chromebooks has happened a while ago, the audio of the Linux games and apps was a real problem. We know how frustrating it is for gamers.

Since chrome os has become an ever-evolving operating system and we are being handed over every other day a new cool functionality. This same applies here.

With chrome os update 79 a flag included to enables mic support for Linux application to further make a reality of Crostini effort on Chrome OS.

If you can wait to appear this feature on your Chromebook, then you may get in your chrome Os core update version of 80 or hopefully with an update 81.

but if you want to enable it right now, then you could do so just using some commands on Crosh shell(chrome os Command shell), here is how to:

Assuming at this point you have already run Linux beta (Crostini Linux)on your chrome books.

• CTRL +ALT+T       (OPen chrosh)
• vmc stop termina     (Hit enter)
• vmc start termina –enable-audio-capture  (Hit enter)
• Wait a bit to return to this command prompt

That’s it, now you can check it with any Linux app you want.