android 离在线sdk 命令词识别（100021）报：java.util.concurrent.ExecutionException: java.lang.Exception: #7, No recognition result matched., reason: 7998, no confidence.请问会是什么原因？以下是关键代码：

  recognizerIntent= new Intent();
  recognizerIntent.putExtra("sample", 16000);
  recognizerIntent.putExtra("language", "cmn-Hans-CN");
  recognizerIntent.putExtra("asr-base-file-path", "/mnt/sdcard/baidu/rs/s_1");
  recognizerIntent.putExtra("prop", 100021);
  JSONObject slotData=new JSONObject();
   slotData.put("usercommand", new JSONArray().put("恭喜发财").put("大展宏图"));
  recognizerIntent.putExtra("slot-data", slotData.toString());