Android - High phone resource usage causing low volume on one headphone?

Question

I am using libpd (Pure Data) on Android in order to make an application that can be used as a low budget hearing aid. My original design for the "audio engine" had 7 filters, and the volume from both headphones was the same. I changed the design to have 14 filters and now the right headphone has low volume.

Running the engine on my laptop produces the same volume on both ears. I tried running all the audio processing on it's own thread, but I am not sure if I did this correctly.

So to boil the question down.

Is low volume on one ear a possible side effect of using too many resources?

Is my implementation of creating a new thread correct?

public class CircleOfFifths extends Activity {

private static final String TAG = "GuitarTuner";
private PdUiDispatcher dispatcher;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    initGui();

    new Thread(new Runnable() { 
        public void run(){        
            try {
                initPd();
                loadPatch();
            } catch (IOException e) {
                Log.e(TAG, e.toString());
                finish();
            }            }
    }).start();



}

private void initGui() {
    setContentView(R.layout.main);
}

private void initPd() throws IOException {
    // Configure the audio glue
    // int sampleRate = AudioParameters.suggestSampleRate();

    int sampleRate = AudioParameters.suggestSampleRate();
    int inpch = AudioParameters.suggestInputChannels();
    int outch = AudioParameters.suggestOutputChannels();
    PdAudio.initAudio(sampleRate, inpch, outch, 4, true);

    // Create and install the dispatcher dispatcher = new PdUiDispatcher();
    // PdBase.setReceiver(dispatcher);
}

private void loadPatch() throws IOException {
    File dir = getFilesDir();
    IoUtils.extractZipResource(getResources().openRawResource(R.raw.patch),
            dir, true);
    File patchFile = new File(dir, "microphone.pd");
    PdBase.openPatch(patchFile.getAbsolutePath());
    PdAudio.startAudio(this);
}

@Override
protected void onResume() {
    super.onResume();
    PdAudio.startAudio(this);
}

@Override
protected void onPause() {
    super.onPause();
    PdAudio.stopAudio();
}
}

score 1 · Accepted Answer · answered Mar 31 '15 at 18:45

Using too much CPU shouldn't effect volume at all. It seems more likely one of your filters is causing a gain less than 1 on that channel.

Your thread looks fine to me. I'm not 100% sure that calling finish on a non-UI thread is legal, but if it isn't you can add a runOnUiThread there

Android - High phone resource usage causing low volume on one headphone?

1 Answers1