Windows Speech Recognition Hello World not working

Question

I am trying to get Windows::Media::SpeechRecognition working on Windows10 but I have trouble making my Hello World App working.

Here is what I did:

• I created a new UWP Blank App in VS2017

• In the OnLaunched() method, I call my Init() method to initialize Speech Recognition:

  void App::Init()
  {
      speechRecognizer = ref new Windows::Media::SpeechRecognition::SpeechRecognizer(Windows::Media::SpeechRecognition::SpeechRecognizer::SystemSpeechLanguage);
  
      Platform::Collections::Vector<String^>^ speech_command_list = ref new Platform::Collections::Vector<String^>();
      speech_command_list->Append(StringReference(L"pause"));
      speech_command_list->Append(StringReference(L"play"));
      speech_command_list->Append(StringReference(L"download"));
      speech_command_list->Append(StringReference(L"test"));
  
      SpeechRecognitionListConstraint^ speech_constraint = ref new SpeechRecognitionListConstraint(speech_command_list);
  
      speechRecognizer->Constraints->Append(speech_constraint);
  
      create_task(speechRecognizer->CompileConstraintsAsync()).then([this](SpeechRecognitionCompilationResult^ compilationResult)
      {
          if (compilationResult->Status == SpeechRecognitionResultStatus::Success)
          {
  
              speechRecognizer->ContinuousRecognitionSession->ResultGenerated += ref new TypedEventHandler<SpeechContinuousRecognitionSession^, SpeechContinuousRecognitionResultGeneratedEventArgs^>(this, &App::OnSpeechRecognized);
              speechRecognizer->HypothesisGenerated += ref new TypedEventHandler<Windows::Media::SpeechRecognition::SpeechRecognizer^, SpeechRecognitionHypothesisGeneratedEventArgs^>(this, &App::OnHypothesisGenerated);
              speechRecognizer->StateChanged += ref new TypedEventHandler<Windows::Media::SpeechRecognition::SpeechRecognizer^, SpeechRecognizerStateChangedEventArgs^>(this, &App::OnStateChanged);
              speechRecognizer->RecognitionQualityDegrading += ref new TypedEventHandler<Windows::Media::SpeechRecognition::SpeechRecognizer^, SpeechRecognitionQualityDegradingEventArgs^>(this, &App::OnQualityIssue);
  
              TimeSpan endSilenceTime;
              endSilenceTime.Duration = 12000000L;
              speechRecognizer->Timeouts->EndSilenceTimeout = endSilenceTime; // (1.2 seconds in nanoseconds)
  
              speechRecognizer->ContinuousRecognitionSession->StartAsync();
          }
          else
          {
              // Handle errors here.
          }
      });
  }
  

• The code compiles, and launches, the compilation of speech constraints is successful, and I break once in the callback OnStateChanged with a new state value as Idle

And that's it. I do not receive any more callbacks when speaking into my mic.

For the record, my mic is properly plugged, it is the default mic on Windows, and it is functional.

Answer 1

I found what was wrong on my application. I post here the answer in case anyone has the same issue.

It turns out that this type of UWP applications comes embedded with a file called Package.appxmanifest, that holds some settings of the application.

This manifest file has a "Capabilities" section, on which I had to turn on "Internet (client)" and "Microphone" capabilities.

After recompilation, everything was working fine.