import 'package:speech_to_text/speech_to_text.dart' as stt;

    stt.SpeechToText speech = stt.SpeechToText();
    bool available = await speech.initialize( onStatus: statusListener, onError: errorListener );
    if ( available ) {
        speech.listen( onResult: resultListener );
    }
    else {
        print("The user has denied the use of speech recognition.");
    }
    // some time later...
    speech.stop()