The problem might be your accent. But you can solve this by modifying the default acoustic model (list of phonemes of each word).
In Sphinx the acoustic model can be found as a text file. It includes some thing like following lines,
HELLO HH AH L OW
HELLO(2) HH EH L OW
THANKS TH AE NG K S
YOUR Y AO R
YOUR(2) Y UH R
TH AE NG K S
is the set of phonemes for the word "THANKS". You can modify these phonemes to suit to your pronunciation.
1. First find WSJ_8gau_13dCep_16k_40mel_130Hz_6800Hz.jar file and extract it.
2. Go to edu\cmu\sphinx\model\acoustic\WSJ_8gau_13dCep_16k_40mel_130Hz_6800Hz\dict folder and open “cmudict.0.6d” file in that folder.
3. Modify the content as it will suit to your pronunciation and save.
4. Zip the extracted hierarchy back as it was and Zip file named should be same as JAR file.
5. Remove “WSJ_8gau_13dCep_16k_40mel_130Hz_6800Hz.jar” file from Project’s CLASSPATH and add “WSJ_8gau_13dCep_16k_40mel_130Hz_6800Hz.zip” instead of it.
You can add more words using the following tool.
http://www.speech.cs.cmu.edu/tools/lmtool-new.html[
^]