This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for the proper prefixes to use 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 spec changes.
The SpeechGrammarList
interface of the Web Speech API represents a list of SpeechGrammar
objects containing words or patterns of words that we want the recognition service to recognize.
Grammar is defined using JSpeech Grammar Format (JSGF.) Other formats may also be supported in the future.
Constructor
SpeechGrammarList.SpeechGrammarList()
- Creates a new
SpeechGrammarList
object.
Properties
SpeechGrammarList.length
Read only- Returns the number of
SpeechGrammar
objects contained in theSpeechGrammarList
.
Methods
SpeechGrammarList.item()
- Standard getter — allows individual
SpeechGrammar
objects to be retrieved from theSpeechGrammarList
using array syntax. SpeechGrammarList.addFromURI()
- Takes a grammar present at a specific URI and adds it to the
SpeechGrammarList
as a newSpeechGrammar
object. SpeechGrammarList.addFromString()
- Takes a grammar present in a specific
DOMString
within the code base (e.g. stored in a variable) and adds it to theSpeechGrammarList
as a newSpeechGrammar
object.
Examples
In our simple Speech color changer example, we create a new SpeechRecognition
object instance using the SpeechRecognition()
constructor, create a new SpeechGrammarList
, add our grammar string to it using the SpeechGrammarList.addFromString
method, and set it to be the grammar that will be recognised by the SpeechRecognition
instance using the SpeechRecognition.grammars
property.
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;
Specifications
Specification | Status | Comment |
---|---|---|
Web Speech API The definition of 'SpeechGrammarList' in that specification. |
Draft |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|
Basic support | 33 [1] | 44 (44) [2] | Not supported | Not supported | Not supported |
weight |
33 [1] | Not supported | Not supported | Not supported | Not supported |
Feature | Android | Chrome | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|
Basic support | ? | (Yes)[1] | ? | 2.5 | Not supported | Not supported | Not supported |
weight |
? | (Yes)[1] | Not supported | Not supported | Not supported | Not supported | Not supported |
- [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"