SpeechRecognitionEvent

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The SpeechRecognitionEvent interface of the Web Speech API represents the event object for the result and nomatch events, and contains all the data associated with an interim or final speech recognition result.

Properties

SpeechRecognitionEvent also inherits properties from its parent interface, Event.

SpeechRecognitionEvent.emma Read only
Returns an Extensible MultiModal Annotation markup language (EMMA) — XML — representation of the result.
SpeechRecognitionEvent.interpretation Read only
Returns the semantic meaning of what the user said.
SpeechRecognitionEvent.resultIndex Read only
Returns the lowest index value result in the SpeechRecognitionResultList "array" that has actually changed.
SpeechRecognitionEvent.results Read only
Returns a SpeechRecognitionResultList object representing all the speech recognition results for the current session.

Examples

This code is excerpted from our Speech color changer example.

recognition.onresult = function(event) {
  // The SpeechRecognitionEvent results property returns a SpeechRecognitionResultList object
  // The SpeechRecognitionResultList object contains SpeechRecognitionResult objects.
  // It has a getter so it can be accessed like an array
  // The first [0] returns the SpeechRecognitionResult at position 0.
  // Each SpeechRecognitionResult object contains SpeechRecognitionAlternative objects that contain individual results.
  // These also have getters so they can be accessed like arrays.
  // The second [0] returns the SpeechRecognitionAlternative at position 0.
  // We then return the transcript property of the SpeechRecognitionAlternative object
  var color = event.results[0][0].transcript;
  diagnostic.textContent = 'Result received: ' + color + '.';
  bg.style.backgroundColor = color;
}

Specifications

Specification Status Comment
Web Speech API
The definition of 'SpeechRecognitionEvent' in that specification.
Draft  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 33 [1] 44 (44) [2] No support No support No support
Feature Android Chrome Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support ? (Yes)[1] ? 2.5 No support No support No support
  • [1] Speech recognition interfaces are currently prefixed on Chrome, so you'll need to prefix interface names appropriately, e.g. webkitSpeechRecognition; You'll also need to serve your code through a web server for recognition to work.
  • [2] Can be enabled via the media.webspeech.recognition.enable flag in about:config, although note that currently speech recognition won't work on Desktop Firefox — it will be properly exposed soon, once the required internal permissions are sorted out.

Firefox OS permissions

To use speech recognition in an app, you need to specify the following permissions in your manifest:

"permissions": {
  "audio-capture" : {
    "description" : "Audio capture"
  },
  "speech-recognition" : {
    "description" : "Speech recognition"
  }
}

You also need a privileged app, so you need to include this as well:

  "type": "privileged"

See also

Document Tags and Contributors

 Contributors to this page: sgiles, chrisdavidmills
 Last updated by: sgiles,