How to add text-to-speech in a Native Android Application

Hello developer, welcome to my new blog in this blog we would learn how to add a text-to-speech feature to our Android App, let's get started without further ado.

Talk - Text to Speech engine ( T T S )

We would be using TTS ( Text-to-Speech ) engine provided by the Android operating system which converts the text to spoken words. TTS technology is being used in Android smartphones, and tablets providing functionalities in Accessibility, Navigation Apps, voice assistance and many more.

In Android we have TextToSpeech class helps us interact with the TTS engine which provides us with different methods to generate Spoken words from the text.

Some features of TTS:-

• It can convert textual Strings or Sentences into Spoken words output.

• It provides us with various controls like we can change the pitch, speed and volume of the output.

• It has multiple languages support: we can provide languages using locale.

• It has Queuing mechanism, where we can queue multiple texts.

Let's dive into the code :

Step 1: Setup your new Android Project

Create a new Android Project, we would be implementing this Project using Java. I am assuming you are familiar with creating Android Projects and basic stuff. Jump to step 2 ;

Step 2: Coding + Understanding

• Activity must implement TextToSpeech.OnInitListener Interface:

In your Activity or Fragment where you will be creating the instance of TextToSpeech, it should implement TextToSpeech.OnInitListener Interface which provides the callback mechanism for receiving the initialization status of the Text-Two-Speech engine. This interface has only one method void oninit(int status) which is called just after the TextToSpeech engine finishes its initialization and returns the status code.

public class MainActivity extends AppCompatActivity implements TextToSpeech.OnInitListener{
@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
`    }
}

• Add necessary permissions to AndroidManifest.xml file :

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WAKE_LOCK" />
  

  The INTERNET permission is required to download the TextToSpeech engine data and the WAKE_LOCK permission is required to not let the device sleep while speaking.

  • Creating an Instance of TextToSpeech + Coding

    [ comments are added to the code carrying explanations ]

       @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);

            // creating an instance of the TTS engine

            TextToSpeech tts = new TextToSpeech(this, this);

            /* I am using viewBinding , speakButton is the id of 
            the button , I am applying setOnClickListener on that 
            as I want it to speak the text when button is clicked .
            */

            binding.speakButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                // setting the text to speak

                    String text = "Like this blog , if you loved it!";

                // Calling the speak method on the tts object created above
                    tts.speak(text, TextToSpeech.QUEUE_FLUSH, null);
                }
            });
    }

speak() method takes the text (which is to be spoken ) as the first argument; the second parameter queueMode which can be TextToSpeech.QUEUE_FLUSH OR TextToSpeech.QUEUE_ADD .

When using TextToSpeech.QUEUE_FLUSH any pending speech synthesis is interrupted and replaced with the new one. The TTS engine stops any ongoing speech and starts speaking the new speech.

When using TextToSpeech.QUEUE_ADD would add the text to the synthesis queue, allowing the TTS engine to speak them one by one without interruption.

And the third parameter we are giving as null is utteranceid as we do not want to assign any specific identifier to the speech requests.

• receiving the CallBack

  onInit is called just after the TextToSpeech engine finishes its initialization and returns the status code.

@Override
    public void onInit(int status) {
        if (status == TextToSpeech.SUCCESS) {

        // adding the language

            int result = tts.setLanguage(Locale.English);

            if (result == TextToSpeech.LANG_MISSING_DATA || result == TextToSpeech.LANG_NOT_SUPPORTED) {
                /* Language data is missing or the language is not supported.
                Handle the error here. */
            } else {

                /* Initialization successful.
                you can add the code for speed , pitch change here
                */

            }
        } else {
            /* TTS initialization failed.
             Handle the error here. */
        }
    }

• overriding onDestroy( )

  onDestroy is an activity lifecycle callback method, here we would release all the memory or resources occupied by the TextTwoSpeech engine as the Activity gets destroyed

•    @Override
        protected void onDestroy() {
            super.onDestroy();
            if (tts != null) {
            // releasing all the occupied resources
                tts.stop();
                tts.shutdown();
            }
        }
  

  Thats all !! You need to do, this for adding a Text to Speech in your Android App , if you have any doubts leave it in the comment I would be glad to answer it .

  If you loved the blog do like it and share it!

  Thank you!!