title: Best sdk or api which convert text into speech
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/416064/text-to-speech-on-iphone">Text to speech on iPhone</a>  </p>
  </blockquote>
  
  
  
  <p>I have a string say "Hello world".
  Please suggest me the best Api or sdk that can convert this text string into speech?</p>