SpeechRecognition

Interfejs SpeechRecognition jest częścią Web Speech API i kontroluje usługę rozpoznawania mowy. Obsługuje również SpeechRecognitionEvent zwracany przez usługę rozpoznawania mowy.

Konstruktor

SpeechRecognition.SpeechRecognition()

Tworzy nowy obiekt SpeechRecognition.

Właściwości

SpeechRecognition dziedziczy równiez właściwości z interfejsu rodzica, EventTarget.

SpeechRecognition.grammars

Tworzy i zwraca kolekcję obiektów SpeechGrammar, które reprezentują zasady gramatyczne akceptowane przez SpeechRecognition.

SpeechRecognition.lang

Tworzy i zwraca język bieżącej instacji SpeechRecognition. Jeśli nie zostanie sprecyzowany domyślnie przyjmie wartość z atrybutu lang, a jeśli i on nie został zdefiniowany - z ustawień językowych przeglądarki.

SpeechRecognition.continuous

Ustawienie przyjęcia ciągłego strumienia mowy lub pojedynczego zwrotu. Domyslnie ustawiony na przyjęcie pojedynczego zwrotu (false.)

SpeechRecognition.interimResults

Ustawienie kontrolujące zwracanie rezultatów pośrednich. Przyjmuje wartości (true) lub (false.) Rezultat pośredni rozpoznawania mowy to rezultat niepełny, uzyskiwany w trakcie rozpoznawania wypowiedzi (np. kiedy metoda SpeechRecognitionResult.isFinal zwraca  false.) 

SpeechRecognition.maxAlternatives

Ustawienie maksymalnej liczby alternatywnych wyników rozpoznawania mowy. Domyślnie - 1.

SpeechRecognition.serviceURI

Specifies the location of the speech recognition service used by the current SpeechRecognition to handle the actual recognition. The default is the user agent's default speech service.

Methods

SpeechRecognition also inherits methods from its parent interface, EventTarget.

SpeechRecognition.abort()

Stops the speech recognition service from listening to incoming audio, and doesn't attempt to return a SpeechRecognitionResult.

SpeechRecognition.start()

Starts the speech recognition service listening to incoming audio with intent to recognize grammars associated with the current SpeechRecognition.

SpeechRecognition.stop()

Stops the speech recognition service from listening to incoming audio, and attempts to return a SpeechRecognitionResult using the audio captured so far.

Events

Listen to these events using addEventListener() or by assigning an event listener to the oneventname property of this interface.

audiostart

Fired when the user agent has started to capture audio.
Also available via the onaudiostart property.

audioend

Fired when the user agent has finished capturing audio.
Also available via the onaudioend property.

end

Fired when the speech recognition service has disconnected.
Also available via the onend property.

error

Fired when a speech recognition error occurs.
Also available via the onerror property.

nomatch

Fired when the speech recognition service returns a final result with no significant recognition. This may involve some degree of recognition, which doesn't meet or exceed the confidence threshold.
Also available via the onnomatch property.

result

Fired when the speech recognition service returns a result — a word or phrase has been positively recognized and this has been communicated back to the app.
Also available via the onresult property.

soundstart

Fired when any sound — recognisable speech or not — has been detected.
Also available via the onsoundstart property.

soundend

Fired when any sound — recognisable speech or not — has stopped being detected.
Also available via the onsoundend property.

speechstart

Fired when sound that is recognised by the speech recognition service as speech has been detected.
Also available via the onspeechstart property.

speechend

Fired when speech recognised by the speech recognition service has stopped being detected.
Also available via the onspeechend property.

start

Fired when the speech recognition service has begun listening to incoming audio with intent to recognize grammars associated with the current SpeechRecognition.
Also available via the onstart property.

Examples

In our simple Speech color changer example, we create a new SpeechRecognition object instance using the SpeechRecognition() constructor, create a new SpeechGrammarList, and set it to be the grammar that will be recognised by the SpeechRecognition instance using the SpeechRecognition.grammars property.

After some other values have been defined, we then set it so that the recognition service starts when a click event occurs (see SpeechRecognition.start().) When a result has been successfully recognised, the SpeechRecognition.onresult handler fires,  we extract the color that was spoken from the event object, and then set the background color of the <html> element to that colour.

var grammar = '#JSGF V1.0; grammar colors; public <color> = aqua | azure | beige | bisque | black | blue | brown | chocolate | coral | crimson | cyan | fuchsia | ghostwhite | gold | goldenrod | gray | green | indigo | ivory | khaki | lavender | lime | linen | magenta | maroon | moccasin | navy | olive | orange | orchid | peru | pink | plum | purple | red | salmon | sienna | silver | snow | tan | teal | thistle | tomato | turquoise | violet | white | yellow ;'
var recognition = new SpeechRecognition();
var speechRecognitionList = new SpeechGrammarList();
speechRecognitionList.addFromString(grammar, 1);
recognition.grammars = speechRecognitionList;
//recognition.continuous = false;
recognition.lang = 'en-US';
recognition.interimResults = false;
recognition.maxAlternatives = 1;

var diagnostic = document.querySelector('.output');
var bg = document.querySelector('html');

document.body.onclick = function() {
  recognition.start();
  console.log('Ready to receive a color command.');
}

recognition.onresult = function(event) {
  var color = event.results[0][0].transcript;
  diagnostic.textContent = 'Result received: ' + color;
  bg.style.backgroundColor = color;
}

Specifications

Browser compatibility

See also

• Web Speech API