title: Problems in adjusting rate/pitch in Alexa SSML
body: <p>I was trying to adjust Alexa talking speed and pitch with following:</p>
  
  <pre><code>outputSpeech: {
              type: "SSML",
              ssml: "&lt;speak&gt;&lt;prosody pitch="+50%"&gt;higher pitch&lt;/prosody&gt;&lt;/speak&gt;"
  },
  </code></pre>
  
  <p>The execution result succeeded, however I noticed <code>"ssml": "&lt;speak&gt;&lt;prosody pitch=NaN"</code>
  and when I went to simulator test, Alexa responded <code>There was a problem with the requested skill's response</code></p>
  
  <p>So I tried couple things:</p>
  
  <pre><code>ssml: "&lt;speak&gt;&lt;prosody rate="150%"&gt;faster pace&lt;/prosody&gt;&lt;/speak&gt;"
  </code></pre>
  
  <p>the execution result fails:
      "SyntaxError: Unexpected number",</p>