rec.cs

private void StartRecordingAndRecognizing()
        {
            string rec = global::Android.Content.PM.PackageManager.FeatureMicrophone;
            if (rec == "android.hardware.microphone")
            {
                var voiceIntent = new Intent(RecognizerIntent.ActionRecognizeSpeech);
                voiceIntent.PutExtra(RecognizerIntent.ExtraLanguageModel, RecognizerIntent.LanguageModelFreeForm);


                voiceIntent.PutExtra(RecognizerIntent.ExtraPrompt, "Speak now");

                voiceIntent.PutExtra(RecognizerIntent.ExtraSpeechInputCompleteSilenceLengthMillis, 1500);
                voiceIntent.PutExtra(RecognizerIntent.ExtraSpeechInputPossiblyCompleteSilenceLengthMillis, 1500);
                voiceIntent.PutExtra(RecognizerIntent.ExtraSpeechInputMinimumLengthMillis, 15000);
                voiceIntent.PutExtra(RecognizerIntent.ExtraMaxResults, 1);
                voiceIntent.PutExtra(RecognizerIntent.ExtraLanguage, Java.Util.Locale.Default);
                _activity.StartActivityForResult(voiceIntent, VOICE);
            }
        }