Can I keep the speech recognizer listening indefinitely?

Question

When I call the startListening method of a SpeechRecognizer object, the speech recognizer starts listening for speech. I would like to create a service that is waiting for speech of a specific keyword: when the user says this keyword and the speech recognizer detects this keyword, then the service becomes ready to receive user voice commands.

To this end, after a new SpeechRecognizer instantiated, I should call its startListening method: can I keep the speech recognizer listening indefinitely?

Answer 1

The Android Speech recognizer can be customized through the intent extra data. See the android documentation.

public static final String EXTRA_SPEECH_INPUT_COMPLETE_SILENCE_LENGTH_MILLIS

The amount of time that it should take after we stop hearing speech to consider the input complete. [...]

public static final String EXTRA_SPEECH_INPUT_MINIMUM_LENGTH_MILLIS Since: API Level 8

The minimum length of an utterance. We will not stop recording before this amount of time. [...]

public static final String EXTRA_SPEECH_INPUT_POSSIBLY_COMPLETE_SILENCE_LENGTH_MILLIS

The amount of time that it should take after we stop hearing speech to consider the input possibly complete. [...]

Set the EXTRA_LANGUAGE_MODEL to websearch to capture only relevant words.

Answer 2

You can implement onError of RecognitionListener interface like this. It is continuously listening in your activity.

@Override public void onError(int error) {     String errorMessage = getErrorText(error);     Log.i(Constants.TAG, "FAILED " + errorMessage);     speech.destroy();     speech = null;     StartListening(); }  private void StartListening() {     speech = SpeechRecognizer.createSpeechRecognizer(this);     speech.setRecognitionListener(this);     recognizerIntent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);     recognizerIntent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_PREFERENCE, "en");     recognizerIntent.putExtra(RecognizerIntent.EXTRA_CALLING_PACKAGE, this.getPackageName());     recognizerIntent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, RecognizerIntent.LANGUAGE_MODEL_WEB_SEARCH);     recognizerIntent.putExtra(RecognizerIntent.EXTRA_MAX_RESULTS, 3);      //if setting.SpeechEnable     speech.startListening(recognizerIntent); }