SpeechRecognizer Class

Definition

Namespace:

Windows.Media.SpeechRecognition

Enables speech recognition with either a default or a custom graphical user interface (GUI).

public ref class SpeechRecognizer sealed : IClosable

/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
/// [Windows.Foundation.Metadata.Activatable(65536, "Windows.Foundation.UniversalApiContract")]
/// [Windows.Foundation.Metadata.Activatable(Windows.Media.SpeechRecognition.ISpeechRecognizerFactory, 65536, "Windows.Foundation.UniversalApiContract")]
class SpeechRecognizer final : IClosable

[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
[Windows.Foundation.Metadata.Activatable(65536, "Windows.Foundation.UniversalApiContract")]
[Windows.Foundation.Metadata.Activatable(typeof(Windows.Media.SpeechRecognition.ISpeechRecognizerFactory), 65536, "Windows.Foundation.UniversalApiContract")]
public sealed class SpeechRecognizer : System.IDisposable

function SpeechRecognizer(language)

Public NotInheritable Class SpeechRecognizer
Implements IDisposable

Inheritance

Object Platform::Object IInspectable SpeechRecognizer

Attributes

ActivatableAttribute ContractVersionAttribute MarshalingBehaviorAttribute

Implements

IClosable IDisposable

Windows requirements

Device family	Windows 10 (introduced in 10.0.10240.0)
API contract	Windows.Foundation.UniversalApiContract (introduced in v1.0)

Remarks

CompileConstraintsAsync must always be called before RecognizeAsync or RecognizeWithUIAsync, even if no constraints are specified in the Constraints property.

Version history

Windows version	SDK version	Value added
1709	16299	TrySetSystemSpeechLanguageAsync

Constructors

SpeechRecognizer()	Creates a new instance of the SpeechRecognizer class.
SpeechRecognizer(Language)	Creates a new instance of the SpeechRecognizer class with a language specifier.

Properties

Constraints	Gets the collection of constraint objects currently added to the SpeechRecognizer object.
ContinuousRecognitionSession	Gets the continuous recognition session object (SpeechContinuousRecognitionSession) associated with this SpeechRecognizer.
CurrentLanguage	Gets the language used for speech recognition.
State	Gets the state of the speech recognizer.
SupportedGrammarLanguages	Gets the collection of languages supported by the custom grammars of the SpeechRecognitionGrammarFileConstraint and SpeechRecognitionListConstraint objects specified in the Constraints property.
SupportedTopicLanguages	Gets the collection of languages supported by the pre-defined, web-service grammars of the SpeechRecognitionTopicConstraint objects specified in the Constraints property.
SystemSpeechLanguage	Gets the speech language of the device specified in Settings > Time & Language > Speech.
Timeouts	Gets how long a speech recognizer ignores silence or unrecognizable sounds (babble) and continues listening for speech input.
UIOptions	Gets the UI settings for the RecognizeWithUIAsync method.

Methods

Close()	Disposes the speech recognizer by freeing, releasing, or resetting allocated resources.
CompileConstraintsAsync()	Asynchronously compile all constraints specified by the Constraints property.
Dispose()	Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
RecognizeAsync()	Begins a speech recognition session for a SpeechRecognizer object.
RecognizeWithUIAsync()	Asynchronously starts a speech recognition session that includes additional UI mechanisms, including prompts, examples, text-to-speech (TTS), and confirmations.
StopRecognitionAsync()	Asynchronously ends the speech recognition session.
TrySetSystemSpeechLanguageAsync(Language)	Asynchronously attempts to set the system language used for speech recognition on an IoT device. Note This method is available only in Embedded mode.

Events

HypothesisGenerated	Occurs during an ongoing dictation session when a recognition result fragment is returned by the speech recognizer.
RecognitionQualityDegrading	This event is raised when an audio problem is detected that might affect recognition accuracy.
StateChanged	This event is raised when a change occurs to the State property during audio capture.

See also

• Windows.Media.SpeechRecognition
• Speech interactions
• Speech recognition and speech synthesis sample
• Holographic voice input sample