Attached files to single - audio

function get_attached_audio($number=NULL){
 
	if($number == NULL ) $number = -1;
 
	global $post;
 
	$args = array(
		'post_type' => 'attachment',
		'numberposts' => $number,
		'post_status' => null,
		'post_parent' => $post->ID,
		'orderby' => 'menu_order'
		); 
 
	$attachments = array_reverse(get_posts($args));
 
	$audios = array();
 
	if ($attachments) {
		foreach ($attachments as $attachment) {
 
			if( $attachment->post_mime_type	== "audio/mpeg"){
				$audio = wp_get_attachment_url($attachment->ID,'full',false);
				$audios[] = array("url" => $attachment->guid, "caption" => $attachment->post_title);				
			}
		}
	}
 
	return $audios;
}