wit.ai speech recognition in PHP

witai_speech.php

<?php
/* wit.ai speech recognition in PHP */
$request = curl_init('https://api.wit.ai/speech');

$headers[] = 'Authorization: Bearer YOURAPIKEY';
$headers[] = 'Content-Type: audio/wav';

curl_setopt($request, CURLOPT_CUSTOMREQUEST, "POST");
curl_setopt($request, CURLOPT_POSTFIELDS, file_get_contents("soundfile.wav"));
curl_setopt($request, CURLOPT_HTTPHEADER, $headers);
curl_setopt($request, CURLOPT_RETURNTRANSFER, true);

$return = curl_exec($request);
echo $return;

THANK YOU VERY MUCH!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

getting blank object including text.