var.cs

        private AVAudioEngine _audioEngine = new AVAudioEngine();
        private SFSpeechRecognizer _speechRecognizer = new SFSpeechRecognizer();
        private SFSpeechAudioBufferRecognitionRequest _recognitionRequest;
        private SFSpeechRecognitionTask _recognitionTask;
        private string _recognizedString;
        private NSTimer _timer;
        private bool isNotContinious;