SpeechRecognitionAlternative
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
The SpeechRecognitionAlternative interface of the Web Speech API represents a single word that has been recognized by the speech recognition service.
Instance properties
SpeechRecognitionAlternative.transcriptRead only-
Returns a string containing the transcript of the recognized word.
SpeechRecognitionAlternative.confidenceRead only-
Returns a numeric estimate between 0 and 1 of how confident the speech recognition system is that the recognition is correct.
Examples
This code is excerpted from our Speech color changer example.
js
recognition.onresult = (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
const color = event.results[0][0].transcript;
diagnostic.textContent = `Result received: ${color}.`;
bg.style.backgroundColor = color;
};
Specifications
| Specification |
|---|
| Web Speech API # speechreco-alternative |
Browser compatibility
| desktop | mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
SpeechRecognitionAlternative | ||||||||||||
confidence | ||||||||||||
transcript | ||||||||||||