//Declare the SpVoice object. ISpeechVoice v=new SpVoiceClass(); //Create a wave stream SpFileStream s =new SpFileStream(); //Create a new .wav file for writing. s.Open("out.wav", SpeechStreamFileMode.SSFMCreateForWrite, false); //Set the .wav file stream as the output for the Voice object v.AudioOutputStream = s; //Call the Speak method now will send the output to the .wav file. v.Speak(txtSpeak, SpeechVoiceSpeakFlags.SVSFDefault); //Close the file s.Close();