Text-to-speech

Set up the backend

Run amplify add predictions, then use the following answers:

? Please select from one of the categories below
  `Convert`
? What would you like to convert? (Use arrow keys)
  `Generate speech audio from text`
? Provide a friendly name for your resource
  `speechGenerator`
? What is the source language? (Use arrow keys)
  `US English`
? Select a speaker (Use arrow keys)
  `Joanna - Female`
? Who should have access? (Use arrow keys)
  `Auth and Guest users`

Run amplify push to create the resources in the cloud.

Working with the API

Open MainActivity.java and add the following code:

private final MediaPlayer mp = new MediaPlayer();
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  Amplify.Predictions.convertTextToSpeech(
    "I like to eat spaghetti",
    result -> playAudio(result.getAudioData()),
    error -> Log.e("MyAmplifyApp", "Conversion failed", error)
private void playAudio(InputStream data) {
  File mp3File = new File(getCacheDir(), "audio.mp3");
  try (OutputStream out = new FileOutputStream(mp3File)) {
    byte[] buffer = new byte[8 * 1_024];
    int bytesRead;
    while ((bytesRead = data.read(buffer)) != -1) {
        out.write(buffer, 0, bytesRead);
    mp.reset();
    mp.setOnPreparedListener(MediaPlayer::start);
    mp.setDataSource(new FileInputStream(mp3File).getFD());
    mp.prepareAsync();
  } catch (IOException error) {
    Log.e("MyAmplifyApp", "Error writing audio file", error);

Open MainActivity.kt and add the following code:

private val mp = MediaPlayer()
override fun onCreate(savedInstanceState: Bundle?) {
  super.onCreate(savedInstanceState)
  setContentView(R.layout.activity_main)
  convertTextToSpeech()
private fun convertTextToSpeech() {
  Amplify.Predictions.convertTextToSpeech("I like to eat spaghetti!",
    { playAudio(it.audioData) },
    { Log.e("MyAmplifyApp", "Failed to convert text to speech", it) }
private fun playAudio(data: InputStream) {
  val mp3File = File(cacheDir, "audio.mp3")
    FileOutputStream(mp3File).use { out ->
      val buffer = ByteArray(8 * 1024)
      var bytesRead: Int
      while (data.read(buffer).also { bytesRead = it } != -1) {
          out.write(buffer, 0, bytesRead)
      mp.reset()
      mp.setOnPreparedListener { obj: MediaPlayer -> obj.start() }
      mp.setDataSource(FileInputStream(mp3File).fd)
      mp.prepareAsync()
  } catch (error: IOException) {
    Log.e("MyAmplifyApp", "Error writing audio file.")

Open MainActivity.kt and add the following code:

private val mp = MediaPlayer()
override fun onCreate(savedInstanceState: Bundle?) {
  super.onCreate(savedInstanceState)
  setContentView(R.layout.activity_main)
  convertTextToSpeech()
private fun convertTextToSpeech() = activityScope.launch {
  val text = "I like to eat spaghetti!"
    val result = Amplify.Predictions.convertTextToSpeech(text)
    playAudio(result.audioData)
  } catch (error: PredictionsException) {
    Log.e("MyAmplifyApp", "Failed to convert text to speech", error)
private fun playAudio(data: InputStream) {
  val mp3File = File(cacheDir, "audio.mp3")
    FileOutputStream(mp3File).use { out ->
      val buffer = ByteArray(8 * 1024)
      var bytesRead: Int
      while (data.read(buffer).also { bytesRead = it } != -1) {
        out.write(buffer, 0, bytesRead)
      mp.reset()
      mp.setOnPreparedListener { obj: MediaPlayer -> obj.start() }
      mp.setDataSource(FileInputStream(mp3File).fd)
      mp.prepareAsync()
  } catch (error: IOException) {
    Log.e("MyAmplifyApp", "Error writing audio file.")

Open MainActivity.java and add the following code:

private final MediaPlayer mp = new MediaPlayer();
protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  RxAmplify.Predictions.convertTextToSpeech("I like to eat spaghetti")
    .subscribe(
      result -> playAudio(result.getAudioData()),
      error -> Log.e("MyAmplifyApp", "Conversion failed", error)
private void playAudio(InputStream data) {
  File mp3File = new File(getCacheDir(), "audio.mp3");
  try (OutputStream out = new FileOutputStream(mp3File)) {
    byte[] buffer = new byte[8 * 1_024];
    int bytesRead;
    while ((bytesRead = data.read(buffer)) != -1) {
      out.write(buffer, 0, bytesRead);
    mp.reset();
    mp.setOnPreparedListener(MediaPlayer::start);
    mp.setDataSource(new FileInputStream(mp3File).getFD());
    mp.prepareAsync();
  } catch (IOException error) {
    Log.e("MyAmplifyApp", "Error writing audio file", error);

This example works on all supported versions of Android. Android API 23 added support for MediaDataSource, which allows for InputStream from Amplify to be read directly without writing to a file.

As a result of running this code, you will hear audio of the text being emitted from your device.

Set up Predictions

Translate language