Web Speech API
The Web Speech API enables you to incorporate voice data into web apps.
The Web Speech API has two parts: SpeechSynthesis
(Text-to-Speech), and SpeechRecognition
(Asynchronous Speech Recognition.)
Web Speech Concepts and Usage
The Web Speech API makes web apps able to handle voice data. There are two components to this API:
-
Speech recognition is accessed via the
SpeechRecognition
interface, which provides the ability to recognize voice context from an audio input (normally via the device's default speech recognition service) and respond appropriately. Generally you'll use the interface's constructor to create a newSpeechRecognition
object, which has a number of event handlers available for detecting when speech is input through the device's microphone. TheSpeechGrammar
interface represents a container for a particular set of grammar that your app should recognize. Grammar is defined using JSpeech Grammar Format (JSGF.) -
Speech synthesis is accessed via the
SpeechSynthesis
interface, a text-to-speech component that allows programs to read out their text content (normally via the device's default speech synthesizer.) Different voice types are represented bySpeechSynthesisVoice
objects, and different parts of text that you want to be spoken are represented bySpeechSynthesisUtterance
objects. You can get these spoken by passing them to theSpeechSynthesis.speak()
method.
For more details on using these features, see Using the Web Speech API.
Web Speech API Interfaces
Speech recognition
SpeechRecognition
-
The controller interface for the recognition service; this also handles the
SpeechRecognitionEvent
sent from the recognition service. SpeechRecognitionAlternative
-
Represents a single word that has been recognized by the speech recognition service.
SpeechRecognitionErrorEvent
-
Represents error messages from the recognition service.
SpeechRecognitionEvent
-
The event object for the
result
andnomatch
events, and contains all the data associated with an interim or final speech recognition result. SpeechGrammar
-
The words or patterns of words that we want the recognition service to recognize.
SpeechGrammarList
-
Represents a list of
SpeechGrammar
objects. SpeechRecognitionResult
-
Represents a single recognition match, which may contain multiple
SpeechRecognitionAlternative
objects. SpeechRecognitionResultList
-
Represents a list of
SpeechRecognitionResult
objects, or a single one if results are being captured incontinuous
mode.
Speech synthesis
SpeechSynthesis
-
The controller interface for the speech service; this can be used to retrieve information about the synthesis voices available on the device, start and pause speech, and other commands besides.
SpeechSynthesisErrorEvent
-
Contains information about any errors that occur while processing
SpeechSynthesisUtterance
objects in the speech service. SpeechSynthesisEvent
-
Contains information about the current state of
SpeechSynthesisUtterance
objects that have been processed in the speech service. SpeechSynthesisUtterance
-
Represents a speech request. It contains the content the speech service should read and information about how to read it (e.g. language, pitch and volume.)
SpeechSynthesisVoice
-
Represents a voice that the system supports. Every
SpeechSynthesisVoice
has its own relative speech service including information about language, name and URI. Window.speechSynthesis
-
Specified out as part of a
[NoInterfaceObject]
interface calledSpeechSynthesisGetter
, and Implemented by theWindow
object, thespeechSynthesis
property provides access to theSpeechSynthesis
controller, and therefore the entry point to speech synthesis functionality.
Errors
For information on errors reported by the Speech API (for example, "language-not-supported"
and "language-unavailable"
), see the following documentation:
Examples
The Web Speech API examples on GitHub contains demos to illustrate speech recognition and synthesis.
Specifications
Specification |
---|
Web Speech API # speechreco-section |
Web Speech API # tts-section |
Browser compatibility
api.SpeechRecognition
BCD tables only load in the browser
api.SpeechSynthesis
BCD tables only load in the browser