I uses the same Flash client that works without background noise on Flash Media Server 7 years ago. It was fine.

This time I use Wowza Media Server. Suddenly this noise audio problem occurs. BACKGROUND ANNOYING NOISE.

I have tried and looked for places on Internet but no place has a solution.

I added Echo Cancellation. Echo Cancellation also looks like not a solution for this background noise because I added Echo cancellation and the noise was still there.
mic = Microphone.getEnhancedMicrophone();
var options : MicrophoneEnhancedOptions = new MicrophoneEnhancedOptions();
options.mode = MicrophoneEnhancedMode.FULL_DUPLEX;
options.autoGain = false;
options.echoPath = 128;
options.nonLinearProcessing = true;
mic['enhancedOptions'] = options;

mic.gain = 40;
mic.rate = 16;
mic.setSilenceLevel(5, 1000);

Anyone knows how to resolve this? I dont know if this is Wowza problem or code problem because this code worked without noise on Flash Media Server 7 years ago. (without even using Echo Cancellation above)