title: IBM Watson text-to-speech curl example not working
body: <p>Here is the command I am using to test the text-to-speech API:</p>
  
  <pre class="lang-none prettyprint-override"><code>/usr/bin/curl -k -u 'USERNAME':'PASSWORD' -X POST \
    --header 'Content-Type: application/json' \
    --header 'Accept: audio/wav' \
    --data '{"text":"hellow world","voice":"en-US_AllisonVoice"}' \
    'https://stream.watsonplatform.net/text-to-speech/api/v1/synthesize' &gt; ./public/138106.wav
  </code></pre>
  
  <p>The command above doesn't seem to generate the desired audio file. I have a bluemix account and the right credentials. An audio file is generated, but it's corrupt.</p>