Thanks a lot,

  My code is working well for Text to Speech and it is also recognizing my voice but it's not properly delivering.

Trying out something under the 

SpeechRecognitionEngine 

class.

    sre.SetInputToDefaultAudioDevice();

                sre.InitialSilenceTimeout = TimeSpan.FromSeconds(3);
                sre.BabbleTimeout = TimeSpan.FromMilliseconds(500);
                sre.EndSilenceTimeout = TimeSpan.FromSeconds(1);
                sre.EndSilenceTimeoutAmbiguous = TimeSpan.FromSeconds(1.5);

                var result = sre.Recognize();

                //var result = sre.EmulateRecognize(ss.ToString());


                if (result.Text == "Yes")
                {
                    rblist1.Checked = true;
                }
                else if (result.Text == "No")
                {
                    rblist2.Checked = true;
                }
                else if(result.Text=="Not Sure")
                {
                    rblist3.Checked = true;
                }
                else
                {
                    rblist1.Checked = false;
                    rblist2.Checked = false;
                    rblist3.Checked = false;
                }

Hope for the best.

Narendran Namachivayam.