rapiro nodejs watson speech to text

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']);
 mic.stderr.pipe(process.stderr);
 stt();
 
 function stt() {
	console.log("openCMDS");
        var speech_to_text = new SpeechToTextV1({
        username: '06fb1d83-0837-49df-a71d-6293c4dd998b',
        password: 'ok742F7q7VHy'
        });

	var params = {
	//content_type: 'audio/wav',
        content_type: 'audio/l16; rate=44100; channels=1',
	model: 'zh-CN_BroadbandModel',
	continuous: true,
	inactivity_timeout: -1
	};

	    var recognizeStream = mic.stdout.pipe(speech_to_text.createRecognizeStream(params)).setEncoding('utf8');
        //mic.stdout.pipe(recognizeStream);//將mic音訊pipe至recognizetream
       
	   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));
  }
 }