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Text to Speech

All text-to-speech functionality is handled through the TextToSpeech interface which can be accessed through the tts property on the main extension: Speech.instance.tts.

Checking for support​

You can check whether text to speech functionality is available on the current device by checking the isSupported property:

if (Speech.instance.tts.isSupported)
{
    // TTS functionality is available on this device
}

Initialise​

You will need to initialise the Text to Speech functionality by calling the initialise() function and awaiting the result.

You can await the result either through the callback function:

Speech.instance.tts.initialise(
        function ( success:Boolean ):void
        {
            trace( "initialise complete:  " + success )
        } 
);

Or via standard events:

  • TextToSpeechEvent.INITIALISE_SUCCESS: If the text to speech functionality was initialised successfully;
  • TextToSpeechEvent.INITIALISE_ERROR: If an error occurred;
Speech.instance.tts.addEventListener( TextToSpeechEvent.INITIALISE_SUCCESS, initialiseSuccessHandler );
Speech.instance.tts.addEventListener( TextToSpeechEvent.INITIALISE_ERROR, initialiseErrorHandler );

Speech.instance.tts.initialise();

function initialiseSuccessHandler( event:TextToSpeechEvent ):void 
{

}

function initialiseErrorHandler( event:TextToSpeechEvent ):void 
{
    
}

Speak​

To use the text to speech output call the speak() method passing in an instance of the Utterance class. This class represents a series of spoken words and access to any available options.

As a minimum you need to pass the text to be spoken to the constructor of the Utterance class:

var utterance:Utterance = new Utterance( "Hello!" );

Then to initiate this output:

Speech.instance.tts.speak( utterance );

Shutdown​

If you no longer require text to speech functionality you can call shutdown() to release any allocated resources and stop any current output. Once you call this method you will need to initialise the TTS functionality again.

Speech.instance.tts.shutdown();

This will also terminate any output currently in progress.