With the function "getEnhancedMicrophone",play will go wrong?

Question

I want to write a program can pull the rtmp stream from FMS or push to FMS,something like video conference system.
At first,the program play normally.
But when I use the function "getEnhancedMicrophone" to get a microphone,it will go wrong.
The voice pauses from time to time.
Actually,I only get the microphone and havn't used it.
Here is part of my codes:
               import mx.controls.Alert;
                              private var nc:NetConnection;
                              private var ns:NetStream;
                              private var video_Pull:Video=new Video();
                              private var pullStreamName:String="c01";
                              private var mic:Microphone=new Microphone();
                              private function init():void
                                        nc = new NetConnection();
                                        nc.objectEncoding = ObjectEncoding.AMF0;
                                        nc.addEventListener(NetStatusEvent.NET_STATUS,netStatusHandler);
                                        nc.client=this;
                                        nc.connect("rtmp://localhost/live");
                                        //add this line will go wrong
                                        //mic=Microphone.getEnhancedMicrophone();
                              public function onBWDone():void{};
                              private function netStatusHandler(evt:NetStatusEvent):void
                                        if(evt.info.code=="NetConnection.Connect.Success")
                                                  pullRTMP(nc,ns,video_Pull,vd_Main,pullStreamName);
                                        else
                                                  Alert.show(evt.info.code);
                              private function pullRTMP(netConnect:NetConnection,netStream:NetStream,video:Video,videoDisplay:VideoDispl ay,streamName:String):void
                                        netStream = new NetStream(netConnect,"connectToFMS");
                                        video.attachNetStream(netStream);
                                        video.smoothing=true;
                                        video.width=videoDisplay.width;
                                        video.height=videoDisplay.height;
                                        videoDisplay.addChild(video);
                                        netStream.play(streamName);
                                        var clientobj:Object=new Object();
                                        clientobj.onMetaData=function():void{}
                                        netStream.client=clientobj;
I use Flash Builder 4.5 and Air 3.1.
This problem had puzzled me few days,someone for help?
Thanks for replies!

Answer 1

I think I can also add，using "getEnhancedMicrophone" is for cancelling the echo...
But I found it didn't work...
Maybe someone could tell me how to cancel the echo in Desktop Development...