Although it does not affect usability of the app it is bad in terms of user privacy perspective - the user might think the app is still recording audio while it is in background, which is scary.
Is there other methods I can call to turn off the microphone access totally, just like the camera?
Got a reply from Tokbox support and they provided a tweak that works as expected!
For your use case, where you don't want to retain the audio access when the app goes into the background, you can try to call
AudioDeviceManager.getAudioDevice().stopCapturer()
to stop the capturer and it will remove the microphone access. If you do this, please make sure to callAudioDeviceManager.getAudioDevice().startCapturer()
when the app comes in the foreground.