IOS Load AudioClip from local

Hi,

I use this code for iOS path:

 public static string GetiPhoneDocumentsPath () 
     { 
 
         string path = Application.dataPath.Substring (0, Application.dataPath.Length - 5); 
         path = path.Substring(0, path.LastIndexOf('/'));  
         return path + "/Documents"; 
 
     }

Documents folder include many .wav files. I want to play this audioClips.

I try this code:

 string filepath = Path.Combine(GetiPhoneDocumentsPath(),SongName);
 AudioClip my = (AudioClip)Resources.Load(filepath, typeof(AudioClip));
 audio.clip = my;
 audio.Play();

but didn't work :(

How can I do???