ECHO PROBLEM

i m using these setting

             microphone = Microphone.getMicrophone();
                microphone.setLoopBack(true);
                microphone.setUseEchoSuppression(true);
                microphone.rate = 11;
                microphone.gain = 50;

i am facing the problem of echo .i am speaking than i can also hera my voice . how to reduce that problem that user can not hear own voice .

And how to reduce echo.