Question

I want to build an android application which will recognize my voice, convert it into text and will show what i just spoke in a toast. i am able to do this by using a button which will launch voice recognizer for me. But now i want to make it work on the bases of my voice only.

The application should trigger voice recognizer and start listening to me only when i start speaking and should stop listening when it senses silence. Just like the functioning of talking tom application. There it records the voice but i want to recognize it using voice recognizer. Some thing like this:

if(no silense)
   Launch Recognizer
else if(silence)
   Stop Recognizer
Show toast

The main problem is that how can i sense if user is speaking something or not before launching voice recognizer. Is there any way to sense noise intensity..??

Secondly, is there any way to launch voice recognizer in the background…??

Is it possible if I can detect audio signal (someone starts speaking) in a background service, which will then immediately launch the voice recognizer to recognize the speech.

Answer 1

Ok I have figured it out. I have used mediaRecorder class for this. When the application launches i start recording the audio using mediaRecoder (or you can provide a button to start and stop the whole process). I check for the amplitude of the audio being recorded by the mediaRecorder. If the amplitude passes over a predefined threshold, I pause the recording and launch the Voice Recognition activity. In OnActivityResult I again resume the recorder.

if(mRecorder != null){
        int i= mRecorder.getMaxAmplitude();   // Getting amplitude 
        Log.d("AMPL : ", String.valueOf(i));

        if(i>20000){      // If amplitude is more than 20000
            onRecord(false);    //Stop recording before launching recognizer
            Intent intent=new Intent(this,VoiceRecognizer.class);   //Launch recognizer activity
            startActivityForResult(intent, 12112);
        }

Alternatively: You can also use RecognitionListener interface as referred in this SO post.