SpeechRecognizer

Kotlin |Java

public final class SpeechRecognizer implements Closeable

Provides an interface for performing on device speech recognition.

It supports both micphone and file descriptor audio input from {@link AudioSource}.

Typical usage:

// 1. Create a SpeechRecognizer with desired options.
val options: SpeechRecognizerOptions =
    speechRecognizerOptions {
        locale = Locale.US
        preferredMode = SpeechRecognizerOptions.Mode.MODE_ADVANCED
    }
val speechRecognizer: SpeechRecognizer = SpeechRecognition.getClient(options)

// 2. Check if the recognition model is available or needs downloading.
launch {
    val status: Int = speechRecognizer.checkStatus()
    if (status == FeatureStatus.DOWNLOADABLE) {
        // 3. If needed, download the model.
        speechRecognizer.download.collect { downloadStatus ->
            when (downloadStatus) {
                is DownloadStatus.DownloadCompleted -> {
                    // Model is ready, start recognition.
                    startMyRecognition(speechRecognizer)
                }
                is DownloadStatus.DownloadFailed -> {
                    // Handle download failure.
                }
                is DownloadStatus.DownloadProgress -> {
                    // Handle download progress can be implemented here.
                }
            }
        }
    } else if (status == FeatureStatus.AVAILABLE) {
        // Model is ready, start recognition.
        startMyRecognition(speechRecognizer)
    } else {
        // Handle other statuses like DOWNLOADING or UNAVAILABLE.
    }
}

// 4. Define your recognition logic.
suspend fun startMyRecognition(SpeechRecognizer recognizer) {
  // Create a request and collect the responses.
  SpeechRecognizerRequest request = ...
  recognizer.startRecognition(request).collect {
      // Process the responses.
  }
}

// 5. Stop recognition when needed.
launch {
    recognizer.stopRecognition()
    recognizer.close()
}

Summary

Public methods
`final @FeatureStatus int`	`checkStatus()` Checks the current availability status of the speech recognition feature.
`void`	`close()` Releases resources associated with the speech recognition engine.
`final @NonNull Flow<@NonNull DownloadStatus>`	`@OptIn(markerClass = [ExperimentalAtomicApi]) download()` Downloads the required model assets for the speech recognition feature if they are not already available.
`final @NonNull Flow<@NonNull SpeechRecognizerResponse>`	`@OptIn(markerClass = [ExperimentalAtomicApi]) startRecognition(@NonNull SpeechRecognizerRequest request)` Starts a streaming speech recognition session when the returning `Flow` is collected.
`final void`	`stopRecognition()` Stops the current speech recognition session.

Public methods

checkStatus

public final @FeatureStatus int checkStatus()

Checks the current availability status of the speech recognition feature.

Returns
`@FeatureStatus int`	`FeatureStatus` indicating feature readiness.

close

public void close()

Releases resources associated with the speech recognition engine.

This should be called when the rewriter is no longer needed.

download

@OptIn(markerClass = [ExperimentalAtomicApi])
public final @NonNull Flow<@NonNull DownloadStatus> download()

Downloads the required model assets for the speech recognition feature if they are not already available.

Use this method to proactively download models before inference. A flow of DownloadStatus reports progress and completion status.

Returns
`@NonNull Flow<@NonNull DownloadStatus>`	`Flow` for collecting to start the download and receive `DownloadStatus`.

startRecognition

@OptIn(markerClass = [ExperimentalAtomicApi])
public final @NonNull Flow<@NonNull SpeechRecognizerResponse> startRecognition(@NonNull SpeechRecognizerRequest request)

Starts a streaming speech recognition session when the returning Flow is collected.

Parameters
`@NonNull SpeechRecognizerRequest request`	the `SpeechRecognizerRequest` containing the audio source and other configuration.

Returns
`@NonNull Flow<@NonNull SpeechRecognizerResponse>`	A `Flow` of `SpeechRecognizerResponse` transformed from `RecognitionResponse`.

stopRecognition

public final void stopRecognition()

Stops the current speech recognition session.

This method gracefully terminates the recognition job. The SpeechRecognizerResponse.CompletedResponse will be sent after the job is fully closed.