Faking audio scrubbing using discrete audio chunks

lecture.php

<?php
// Include Twilio helper library
require("Services/Twilio.php");

// Instantiate Twilio Response object to render TwiML.
$response = new Services_Twilio_Twiml();
$gather = $response->gather(array('numDigits' => 1));

if (isset($_REQUEST['Digits'])) {
    $gather-say('Playing part '.$_REQUEST['Digits']);
    $gather->play('part'.$_REQUEST['Digits'].'.mp3');
} else {
    // No digit set - play first track
    $gather->play('part1.mp3');
}

print $response;
?>