Published: 14. 3. 2017   Category: GNU/Linux

Microphone problems in MacOSX

The way MacOSX is handling an input audio stream coming from the internal microphone is pretty buggy. Usually, you will find that your microphone is not working a minute before meeting or in the worst case when you need to say something superimportant. This bug is even more tricky because your speaker works and when you check your sound card settings in System Preferences and the audio monitor shows signal amplitude here.

So how to be sure that your mic is sound?

  1. Go to: Allow chrome to access your microphone and see if there is a signal on an oscilloscope type display. If yes, you are fine.
  2. What to do if there is no signal:
    • Simple solution: restart your computer.
    • Engineering solution (does not require reboot):
      1. Open Terminal application.
      2. Switch to admin user: su - admin
      3. Check a process ID of coreaudiod process: ps xau | grep coreaud

        The output of the ps command will look similar to this:

        _coreaudiod      24243   4.4  0.1  2475428   8204   ??  Ss   10:39PM
        1:01.89 /usr/sbin/coreaudiod
        admin             33520   0.0  0.0  2423384    232 s010  R+   10:44AM
        0:00.00 grep coreaud
      4. Send SIGTERM to coreaudiod: sudo kill -s TERM 24243

        You need to provide correct process ID (there will be a different number than 24243) to send the signal with the kill command.

      5. The operating system will automatically restart the core audio layer and after you will reconnect to your hangout the microphone will work again.