Свойство onStart
Поток start событий, обрабатываемых этим SpeechRecognition.
Реализация
Stream<Event> get onStart => startEvent.forTarget(this);
© 2012 the Dart project authors
Licensed under the BSD 3-Clause "New" or "Revised" License.
https://api.dart.dev/stable/2.18.5/dart-html/SpeechRecognition/onStart.html
