title: how to get the microphone streamed directly to the watson speechToText service
body: <p>We'd like to pipe microphone directly to waton speech to text service , but it seems that we have to go through .wav first ? please take a look at the following codes, In particular I was trying to get the microphone streamed directly to the speechToText service. I believe this is the most common way of using mic, not piping it into a .wav and then stream the .wav file to stt:</p>
  
  <pre><code>var mic;
   var SpeechToTextV1 = require('watson-developer-cloud/speech-to-text/v1');
   var fs = require('fs');
   var watson = require('watson-developer-cloud');
   var cp = require('child_process');
    mic = cp.spawn('arecord', ['--device=plughw:1,0', '--format=S16_LE', '--rate=44100', '--channels=1']); //, '--duration=10'
    mic.stderr.pipe(process.stderr);
    stt();
  
    function stt() {
       console.log("openCMDS");
           var speech_to_text = new SpeechToTextV1({
           username: '',
           password: ''
           });
       var params = {
       content_type: 'audio/wav',
       model: 'zh-CN_BroadbandModel',
       continuous: true,
       inactivity_timeout: -1
       };
       recognizeStream = speech_to_text.createRecognizeStream(params);
           mic.stdout.pipe(recognizeStream);
           //mic.stdout.pipe(require('fs').createWriteStream('test.wav')); 
  
           // Pipe in the audio.
           fs.createReadStream('test.wav').pipe(recognizeStream);
           recognizeStream.pipe(fs.createWriteStream('transcription.txt'));
       recognizeStream.setEncoding('utf8'); 
       console.log("start record");
          recognizeStream.on('data', function(event) { onEvent('Data:', event); });
          recognizeStream.on('error', function(event) { onEvent('Error:', event); });
          recognizeStream.on('close', function(event) { onEvent('Close:', event); });
   // Display events on the console.
   function onEvent(name, event) {
       console.log(name, JSON.stringify(event, null, 2));
        }
  
   }
  </code></pre>