docs(Text to Speech): Add WebSocket example in README

Author: lpatino10

text-to-speech/README.md

@@ -27,4 +27,44 @@ Voices voices = service.listVoices().execute();
 System.out.println(voices);
 ```
 
+## Usage with WebSockets
+The Watson Text to Speech service supports the use of WebSockets as an alternative to the `synthesize()` method, which converts text to speech. Here is an example of using the WebSocket version of the method to get an audio file:
+```java
+TextToSpeech service = new TextToSpeech();
+service.setUsernameAndPassword("<username>", "<password>");
+
+String text = "It's beginning to look a lot like Christmas";
+SynthesizeOptions synthesizeOptions = new SynthesizeOptions.Builder()
+  .text(text)
+  .accept(SynthesizeOptions.Accept.AUDIO_OGG_CODECS_OPUS)
+  .build();
+
+// a callback is defined to handle certain events, like an audio transmission or a timing marker
+// in this case, we'll build up a byte array of all the received bytes to build the resulting file
+final ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
+service.synthesizeUsingWebSocket(synthesizeOptions, new BaseSynthesizeCallback() {
+  @Override
+  public void onAudioStream(byte[] bytes) {
+    // append to our byte array
+    try {
+      byteArrayOutputStream.write(bytes);
+    } catch (IOException e) {
+      e.printStackTrace();
+    }
+  }
+});
+
+// quick way to wait for synthesis to complete, since synthesizeUsingWebSocket() runs asynchronously
+Thread.sleep(5000);
+
+// create file with audio data
+String filename = "synthesize_websocket_test.ogg";
+OutputStream fileOutputStream = new FileOutputStream(filename);
+byteArrayOutputStream.writeTo(fileOutputStream);
+
+// clean up
+byteArrayOutputStream.close();
+fileOutputStream.close();
+```
+
 [text_to_speech]: https://console.bluemix.net/docs/services/text-to-speech/index.html