How to play audio through earpiece in android 12?

Question

I am developing a voice call app for android using PeerJS and WebView. And I want the audio to play through the earpiece. Here is my code,

private fun initAudio(){
  am = getSystemService(AUDIO_SERVICE) as AudioManager
  volumeControlStream = AudioManager.STREAM_VOICE_CALL
  am.mode = AudioManager.MODE_IN_COMMUNICATION
  am.isSpeakerphoneOn = false//<= not working in android 12
}

private fun toggleSpeakerMode(){
  am.isSpeakerphoneOn = !am.isSpeakerphoneOn // <= final value is always true in android 12
}

The above code works fine on older versions of android, but not in android 12 (emulator). am.isSpeakerphoneOn is always true in android 12. Am I doing something wrong here? Or is it a bug in the emulator?

Answer 1

there is a new API call in Android 12/S/API 31, setCommunicationDevice(AudioDeviceInfo). for switching between speaker an built-in earpiece now we can use:

ArrayList<Integer> targetTypes = new ArrayList<>();
if (earpieceMode) {
    targetTypes.add(AudioDeviceInfo.TYPE_BUILTIN_EARPIECE);
} else { // play out loud
    targetTypes.add(AudioDeviceInfo.TYPE_BUILTIN_SPEAKER);
}
// more targetTypes may be added in some cases
// set up will pick and first available, so order matters

List<AudioDeviceInfo> devices = audioManager.getAvailableCommunicationDevices();
outer:
for (Integer targetType : targetTypes) {
    for (AudioDeviceInfo device : devices) {
        if (device.getType() == targetType) {
            boolean result = audioManager.setCommunicationDevice(device);
            Log.i("AUDIO_MANAGER", "setCommunicationDevice type:" + targetType + " result:" + result);
            if (result) break outer;
        }
    }
}

mode change isn't needed (but for voip calls is strongly suggested) and my streams are AudioManager.STREAM_VOICE_CALL type (where applicable)