Using Grammar with Web Speech API

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Yes, There are questions like this one but they're too old...Now grammar is fully supported in chrome.link: https://developer.mozilla.org/en-US/docs/Web/API/SpeechRecognition/grammars

I'm using Web Speech API to implement Speech Recognition. The grammars property of the SpeechRecognition interface returns and sets a collection of SpeechGrammar objects that represent the grammars that will be understood by the current SpeechRecognition. I'm using the last update of chrome and 'they' say grammar is supported in chrome.

Most of the times when I say "Who are you" Web Speech Recognized it as "How are you". How I can set the sentence "Who are you", for example,to possible inputs?

I tried it a couple of hours, pulling my hair without any success....

Here is the code :

  var SpeechRecognition = SpeechRecognition || webkitSpeechRecognition;
  var SpeechGrammarList = SpeechGrammarList || webkitSpeechGrammarList;
  var SpeechRecognitionEvent = SpeechRecognitionEvent || webkitSpeechRecognitionEvent;

  var recognition = new SpeechRecognition();
  var speechRecognitionList = new SpeechGrammarList();
  recognition.grammars = speechRecognitionList;
  recognition.lang = 'en-GB';
  recognition.interimResults = false;
  recognition.maxAlternatives = 1;

  recognition.start();

  recognition.onresult = function(event) {

    var speechResult = event.results[0][0].transcript;
 // We get speechResult to do something with it here

    console.log('Confidence: ' + event.results[0][0].confidence);
  }

  recognition.onspeechend = function() {
    recognition.stop();
    console.log('Speech ended!');
  }

  recognition.onerror = function(event) {
 console.log('Error occurred in recognition: ' + event.error);
  }

  recognition.onaudiostart = function(event) {
      //Fired when the user agent has started to capture audio.
      console.log('SpeechRecognition.onaudiostart');
  }

  recognition.onaudioend = function(event) {
      //Fired when the user agent has finished capturing audio.
      console.log('SpeechRecognition.onaudioend');
  }

  recognition.onend = function(event) {
      //Fired when the speech recognition service has disconnected.
      console.log('SpeechRecognition.onend');
  }

  recognition.onnomatch = function(event) {
      //Fired when the speech recognition can't recognise speech
      console.log('SpeechRecognition.onnomatch');
  }

  recognition.onsoundstart = function(event) {
      //Fired when any sound — recognisable speech or not — has been detected.
      console.log('SpeechRecognition.onsoundstart');
  }

  recognition.onsoundend = function(event) {
      //Fired when no sound present
      console.log('SpeechRecognition.onsoundend');
  }

  recognition.onspeechstart = function (event) {
      //Fired when speech starts
      console.log('SpeechRecognition.onspeechstart');
  }
  recognition.onstart = function(event) {
      //Fired when the speech recognition service has begun listening
      console.log('SpeechRecognition.onstart');
  }
webspeech-api grammar javascript
3 Answers

looks like webkitSpeechGrammarList is under the hood in chrome, try this if you are on the latest version of google chrome:

var SpeechGrammarList = SpeechGrammarList || window.webkitSpeechGrammarList
var speechRecognitionList = new SpeechGrammarList();
user_43784750

There is a way of adding another grammar to the grammar list and add more weight (importance) to it:

const grammar = '#JSGF V1.0; grammar colors; public <color> = aqua | azure | beige | bisque | black | blue | brown | chocolate | coral | crimson | cyan | fuchsia | ghost | white | 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 ;'
const recognition = new SpeechRecognition()
const speechRecognitionList = new SpeechGrammarList()
speechRecognitionList.addFromString(grammar, 1)
recognition.grammars = speechRecognitionList

Check out speechGrammarListInstance.addFromString.

It might not be the perfect solution for your use case. Web Speech API does not seem to be very flexible in terms of controlling the grammar.

user_17728230
user_94156850
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