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System.Speech.Synthesis Namespace

The N:System.Speech.Synthesis namespace contains classes for initializing and configuring a speech synthesis engine, for creating prompts, for generating speech, for responding to events, and for modifying voice characteristics.

Initialize and Configure

The SpeechSynthesizer class provides access to the functionality of a speech synthesis engine that is installed on the host computer. Installed speech synthesis engines are represented by a voice, for example Microsoft Anna. A SpeechSynthesizer instance initializes to the default voice. To configure a SpeechSynthesizer instance to use one of the other installed voices, call the SelectVoice(String) or SelectVoiceByHints() methods. To get information about which voices are installed, use the GetInstalledVoices() method.

You can route the output of the SpeechSynthesizer to a stream, a file, the default audio device, or to a null device by using one of the methods in the SpeechSynthesizer class whose name begins with “SetOutputTo”.

Create Prompts

Use one the methods of the PromptBuilder class whose name begins with “Append” to build content for prompts from text, Speech Synthesis Markup Language (SSML), files containing text or SSML markup, or prerecorded audio files.

See Constructing a Complex Prompt in the System Speech Programming Guide for .NET Framework 4.0 for more information and examples.

Generate Speech

To generate speech from a string or from a Prompt or PromptBuilder object, use the Speak() or the SpeakAsync() methods. To generate speech from SSML markup, use the SpeakSsml(String) or the SpeakSsmlAsync(String) methods. See Speech Synthesis Markup Language Reference for a guide to SSML markup.

You can guide the pronunciation of words by using the AppendTextWithHint() or AppendTextWithPronunciation(String, String) methods, and by adding or removing lexicons for a SpeechSynthesizer instance using the AddLexicon(Uri, String) and RemoveLexicon(Uri) methods.

Respond to Events

The SpeechSynthesizer class includes events that inform a speech application that the SpeechSynthesizer encountered a specific feature in a prompt, as reported by the SpeakProgressEventArgs, BookmarkReachedEventArgs, PhonemeReachedEventArgs, and VisemeReachedEventArgs classes.

To get information about the beginning and end of the speaking of a prompt by the SpeechSynthesizer, use the SpeakStartedEventArgs and SpeakCompletedEventArgs classes.

See Using Speech Synthesis Events in the System Speech Programming Guide for .NET Framework 4.0 for more information and examples.

Modify Voice Characteristics

The PromptStyle class and StartStyle(PromptStyle) and AppendText() methods let you modify characteristics of a SpeechSynthesizer voice using Emphasis, Rate, and Volume parameters. To modify characteristics of a voice such as culture, age, and gender, use one of the StartVoice() methods of the PromptBuilder class or the SelectVoiceByHints() methods of the SpeechSynthesizer class.

See Controlling Voice Attributes in the System Speech Programming Guide for .NET Framework 4.0 for more information.

Public classBookmarkReachedEventArgsReturns data from the BookmarkReached event.
Public classFilePromptRepresents a prompt created from a file.
Public classInstalledVoiceContains information about a speech synthesis voice installed in Windows.
Public classPhonemeReachedEventArgsReturns data from the PhonemeReached event.
Public classPromptRepresents information about what can be rendered, either text or an audio file, by the SpeechSynthesizer.
Public classPromptBuilderCreates an empty Prompt object and provides methods for adding content, selecting voices, controlling voice attributes, and controlling the pronunciation of spoken words.
Public classPromptEventArgsRepresents the base class for EventArgs classes in the System.Speech.Synthesis namespace.
Public classPromptStyleDefines a style for speaking prompts that consists of settings for emphasis, rate, and volume.
Public classSpeakCompletedEventArgsReturns notification from the SpeakCompleted event.
Public classSpeakProgressEventArgsReturns data from the SpeakProgress event.
Public classSpeakStartedEventArgsReturns notification from the SpeakStarted event.
Public classSpeechSynthesizerProvides access to the functionality of an installed a speech synthesis engine.
Public classStateChangedEventArgsReturns data from the StateChanged event.
Public classVisemeReachedEventArgsReturns data from the VisemeReached event.
Public classVoiceChangeEventArgsReturns data from the VoiceChange event.
Public classVoiceInfoRepresents an installed speech synthesis engine.

Public enumerationPromptBreakEnumerates values for intervals of prosodic separation (breaks) between word boundaries.
Public enumerationPromptEmphasisEnumerates values for levels of emphasis in prompts.
Public enumerationPromptRateEnumerates values for the speaking rate of prompts.
Public enumerationPromptVolumeEnumerates values for volume levels (loudness) in prompts.
Public enumerationSayAsEnumerates the content types for the speaking of elements such as times, dates, and currency.
Public enumerationSynthesisMediaTypeEnumerates the types of media files.
Public enumerationSynthesisTextFormatEnumerates the types of text formats that may be used to construct a Prompt object.
Public enumerationSynthesizerEmphasisEnumerates levels of synthesizer emphasis.
Public enumerationSynthesizerStateEnumerates values for the state of the SpeechSynthesizer.
Public enumerationVoiceAgeDefines the values for the age of a synthesized voice.
Public enumerationVoiceGenderDefines the values for the gender of a synthesized voice.