Android sphinx speech recognition - add multiple keyphrases to recognizer

[misha mihail]

Hello, thank you for your time.
I am willing to build speech recognition with only two word phrases "next screen" and "back screen".
Add only one keyphrase is working well.
I will add my code.

public class VoiceService extends Service implements
RecognitionListener {

private static final String LOG_TAG = VoiceService.class.getSimpleName();

/* Named searches allow to quickly reconfigure the decoder */
private static final String KWS_SEARCH = "wakeup";

/* Keyword we are looking for to activate menu */
private static final String KEYPHRASE = "next screen";

private SpeechRecognizer recognizer;

@Nullable
@Override
public IBinder onBind(Intent intent) {
    return null;
}

@Override
public int onStartCommand(Intent intent, int flags, int startId) {

    // Check if user has given permission to record audio
    int permissionCheck = ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.RECORD_AUDIO);
    if (permissionCheck == PackageManager.PERMISSION_GRANTED) {
        runRecognizerSetup();
    }
    return super.onStartCommand(intent, flags, startId);
}

private void runRecognizerSetup() {
    // Recognizer initialization is a time-consuming and it involves IO,
    // so we execute it in async task
    new AsyncTask<Void, Void, Exception>() {
        @Override
        protected Exception doInBackground(Void... params) {
            try {
                Assets assets = new Assets(VoiceService.this);
                File assetDir = assets.syncAssets();
                setupRecognizer(assetDir);
            } catch (IOException e) {
                return e;
            }
            return null;
        }

        @Override
        protected void onPostExecute(Exception result) {
            if (result != null) {
                Log.i(LOG_TAG, "Failed to init recognizer ");
            } else {
                switchSearch(KWS_SEARCH);
            }
        }
    }.execute();
}

@Override
public void onDestroy() {
    super.onDestroy();

    if (recognizer != null) {
        recognizer.cancel();
        recognizer.shutdown();
    }
}

/**
 * In partial result we get quick updates about current hypothesis. In
 * keyword spotting mode we can react here, in other modes we need to wait
 * for final result in onResult.
 */
@Override
public void onPartialResult(Hypothesis hypothesis) {
    if (hypothesis == null)
        return;

    String text = hypothesis.getHypstr();
    if (text.contains(KEYPHRASE)) {
        Toast.makeText(this, "onPartialResult text=" + text, Toast.LENGTH_SHORT).show();
        switchSearch(KWS_SEARCH);
    }

    Log.i(LOG_TAG, "onPartialResult text=" +text);
}

/**
 * This callback is called when we stop the recognizer.
 */
@Override
public void onResult(Hypothesis hypothesis) {
    if (hypothesis != null) {
        String text = hypothesis.getHypstr();
        Log.i(LOG_TAG, "onResult text=" +text);

    }
}

@Override
public void onBeginningOfSpeech() {
    Log.i(LOG_TAG, "onBeginningOfSpeech");
}

/**
 * We stop recognizer here to get a final result
 */
@Override
public void onEndOfSpeech() {
    if (!recognizer.getSearchName().contains(KWS_SEARCH))
        switchSearch(KWS_SEARCH);
    Log.i(LOG_TAG, "onEndOfSpeech");
}

private void switchSearch(String searchName) {
    Log.i(LOG_TAG, "switchSearch searchName = " + searchName);
    recognizer.stop();

    // If we are not spotting, start listening with timeout (10000 ms or 10 seconds).
    recognizer.startListening(searchName, 10000);
}

private void setupRecognizer(File assetsDir) throws IOException {
    // The recognizer can be configured to perform multiple searches
    // of different kind and switch between them

    recognizer = SpeechRecognizerSetup.defaultSetup()
            .setAcousticModel(new File(assetsDir, "en-us-ptm"))
            .setDictionary(new File(assetsDir, "cmudict-en-us.dict"))

            .setRawLogDir(assetsDir) // To disable logging of raw audio comment out this call (takes a lot of space on the device)
            .setKeywordThreshold(1e-45f) // Threshold to tune for keyphrase to balance between false alarms and misses
            .setBoolean("-allphone_ci", true)  // Use context-independent phonetic search, context-dependent is too slow for mobile

            .getRecognizer();
    recognizer.addListener(this);

    /** In your application you might not need to add all those searches.
     * They are added here for demonstration. You can leave just one.
     */

    // Create keyword-activation search.

    recognizer.addKeyphraseSearch(KWS_SEARCH, KEYPHRASE);

}

@Override
public void onError(Exception error) {
    Log.i(LOG_TAG, "onError " + error.getMessage());
}

@Override
public void onTimeout() {
    switchSearch(KWS_SEARCH);
    Log.i(LOG_TAG, "onTimeout");
}

}

This code works well, i just want add more keyphrase like "back screen"

So i added code

KEYPHRASE1 = "back screen"

recognizer.addKeyphraseSearch(KWS_SEARCH, KEYPHRASE1);

//onpartialResult fuction

if (text.contains(KEYPHRASE1)) {
Toast.makeText(this, "onPartialResult text=" + text, Toast.LENGTH_SHORT).show();
switchSearch(KWS_SEARCH);
}

Add gram is another concept, i believe and accuracy is too low (without trained, my opinion).
So could you help me?
Thank you.

[Nickolay V. Shmyrev]

You can use keyphrase list file:

https://stackoverflow.com/questions/25748113/recognizing-multiple-keywords-using-pocketsphinx