如何检查Android麦克风是否可用？

Question

I am currently programming an app that uses the microphone to query the sound level. I am using AlarmManager to query the sound level every minute. The problem I am facing is that I discovered if I am using another app that uses the microphone too (eg decibel level reader) my app will crash because the microphone is not available. Is there a way to check if the microphone is currently being used or not?

Answer 1

Try Catching exception, as you get exception when you try to use microphone you can handle it.

"The microphone will actually prepare fine even if the microphone is in use"

OR this code snippet may give you an idea

//returns whether the microphone is available
    public static boolean getMicrophoneAvailable(Context context) {
        MediaRecorder recorder = new MediaRecorder();
            recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        recorder.setOutputFormat(MediaRecorder.OutputFormat.DEFAULT);
        recorder.setAudioEncoder(MediaRecorder.AudioEncoder.DEFAULT);
        recorder.setOutputFile(new File(context.getCacheDir(), "MediaUtil#micAvailTestFile").getAbsolutePath());
        boolean available = true;
        try { 
            recorder.prepare();
            recorder.start();

        }
        catch (Exception exception) {
            available = false;
        }
        recorder.release();
        return available;
    }

Answer 2

if you use AudioRecord then call startRecording() and after that you should check recorder's state: getRecordingState() . If recording was started successfully (it means mic is available), it will return 3 ( AudioRecord.RECORDSTATE_RECORDING ) otherwise it will return 1 ( AudioRecord.RECORDSTATE_STOPPED )

Here's code for this function in Kotlin:

private fun isMicAvailable(audioRecord: AudioRecord): Boolean {
    audioRecord.startRecording()
    val isAvailable = audioRecord.recordingState == AudioRecord.RECORDSTATE_RECORDING
    audioRecord.stop()
    audioRecord.release()
    return isAvailable
}

Answer 3

I also want to detect whether microphone is being used or not. My solution is using AudioManager to get current mode.

AudioManager am = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
if (am.getMode() == AudioManager.MODE_NORMAL){
   //microphone is available.
}

Other modes usage like MODE_IN_COMMUNICATION, MODE_IN_CALL, please check https://developer.android.com/reference/android/media/AudioManager.html#MODE_NORMAL