OpenNI and/or SAPI

i am using SAPI,It works perfect in debug mode. but after building it, it crashed down when it comes to GetVoice function.

Here's my code.

 private SpVoice _voiceNotice = null;

   _voiceNotice = new SpVoice();
     try
     {
         SpeechLib.ISpeechObjectTokens objTokens = _voiceNotice.GetVoices("", "");
         const string useVoice = "ScanSoft Mei-Ling_Full_22kHz";
         int useIndex = -1;
         for (int i = 0; i < objTokens.Count; i++)
         {
             if (objTokens.Item(i).GetDescription() == useVoice)
             {
                 useIndex = i;
                 break;
             }
         }
         if (useIndex == -1)
         {
             UnityEngine.Debug.Log("无法找到ScanSoft Mei-Ling_Full_22kHz 声音");
             useIndex = 0;
         }
         _voiceNotice.Voice = objTokens.Item(useIndex);
     }
     catch (System.Exception ex)
     {
         print(ex.Message);
     }