import 'package:speech_recognition/speech_recognition.dart';

//..
_speech = SpeechRecognition();
// The flutter app not only call methods on the host platform,
// it also needs to receive method calls from host.
_speech.setAvailabilityHandler((bool result) 
  => setState(() => _speechRecognitionAvailable = result));
// handle device current locale detection
_speech.setCurrentLocaleHandler((String locale) =>
 setState(() => _currentLocale = locale));
_speech.setRecognitionStartedHandler(() 
  => setState(() => _isListening = true));
// this handler will be called during recognition. 
// the iOS API sends intermediate results,
// On my Android device, only the final transcription is received
_speech.setRecognitionResultHandler((String text) 
  => setState(() => transcription = text));
_speech.setRecognitionCompleteHandler(() 
  => setState(() => _isListening = false));
// 1st launch : speech recognition permission / initialization
_speech
    .activate()
    .then((res) => setState(() => _speechRecognitionAvailable = res));
//..
speech.listen(locale:_currentLocale).then((result)=> print('result : $result'));
// ...
speech.cancel();
// ||
speech.stop();