layout_text_to_speech.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="<http://schemas.android.com/apk/res/android>"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16dp">
    
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content" 
        android:hint="Enter text here!"
        android:id="@+id/textToSpeak"/>
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" 
        android:layout_centerHorizontal="true"
        android:layout_below="@id/textToSpeak"
        android:id="@+id/btnSpeak"/>

</RelativeLayout>

AndroidTextToSpeechActivity.java

public class AndroidTextToSpeechActivity extends Activity implements
        TextToSpeech.OnInitListener {

    EditText textToSpeak = null;
    Button btnSpeak = null;
    TextToSpeech tts;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        textToSpeak = findViewById(R.id.textToSpeak);
        btnSpeak = findViewById(R.id.btnSpeak);
        btnSpeak.setEnabled(false);
        tts = new TextToSpeech(this, this);
        btnSpeak.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    speakOut();
                }
            });
    }

@Override
public void onDestroy() {
    // Don't forget to shutdown tts!
    if (tts != null) {
        tts.stop();
        tts.shutdown();
    }
    super.onDestroy();
}

@Override
public void onInit(int status) {
    if (status == TextToSpeech.SUCCESS) {
        int result = tts.setLanguage(Locale.US);

if (result == TextToSpeech.LANG_MISSING_DATA
        || result == TextToSpeech.LANG_NOT_SUPPORTED) {
    Log.e("TTS", "This Language is not supported");
} else {
    btnSpeak.setEnabled(true);
    speakOut();
}
} else {
Log.e("TTS", "Initilization Failed!");
}
}

private void speakOut() {
String text = textToSpeak.getText().toString();
if(text == null || text.isEmpty())
return;

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
    String utteranceId=this.hashCode() + "";
    tts.speak(text, TextToSpeech.QUEUE_FLUSH, null, utteranceId);
} else {
    tts.speak(text, TextToSpeech.QUEUE_FLUSH, null);
}
}
}

The language to be spoken can be set by providing a [Locale](<https://developer.android.com/reference/java/util/Locale.htm>) to the [setLanguage()](<https://developer.android.com/reference/android/speech/tts/TextToSpeech.html#setLanguage(java.util.Locale)>) method:

tts.setLanguage(Locale.CHINESE); // Chinese language

The number of supported languages varies between Android levels. The method [isLanguageAvailable()](<https://developer.android.com/reference/android/speech/tts/TextToSpeech.html#isLanguageAvailable(java.util.Locale)>) can be used to check if a certain language is supported:

tts.isLanguageAvailable(Locale.CHINESE);

The speech pitch level can be set by using the [setPitch()](<https://developer.android.com/reference/android/speech/tts/TextToSpeech.html#setPitch(float)>) method. By default, the pitch value is 1.0. Use values less than 1.0 to decrease the pitch level or values greater than 1.0 to increase the pitch level:

tts.setPitch(0.6);

The speech rate can be set using [setSpeechRate()](<https://developer.android.com/reference/android/speech/tts/TextToSpeech.html#setSpeechRate(float)>). The default speech rate is 1.0. The speech rate can be doubled by setting it to 2.0 or made half by setting it to 0.5:

tts.setSpeechRate(2.0);