Acoustic Model Discussions

NullPointerException when load n-gram language model
User: Pacer
Date: 7/22/2016 8:59 am
Views: 3139
Rating: 0


I managed to train my german 8khz accoustic model with the voxforge-de-20141117 package. It took quite a while to fix all the sentence errors (numbers, signs, missspelling etc.) but finally I got a working model for our telephony purposes. 

We are using a little grammar to filter only the words we want to recognize. All works fine, except when I disable the usage of the grammer to allow Sphinx4 to recognize every word. Then, and only then, I get the following NullPointerExcepttion when loading the LM:

Jul 22, 2016 2:08:18 PM edu.cmu.sphinx.linguist.language.ngram.trie.NgramTrieModel allocate

INFORMATION: Loading n-gram language model from: jar:file:/webapps/qta/WEB-INF/lib/sphinx4-data-5prealpha-20160531.163451-...e_de.lm.bin
at edu.cmu.sphinx.linguist.language.ngram.trie.NgramTrieQuant.setTable(
at edu.cmu.sphinx.linguist.language.ngram.trie.BinaryLoader.readQuant(
at edu.cmu.sphinx.linguist.language.ngram.trie.NgramTrieModel.allocate(
at edu.cmu.sphinx.linguist.lextree.LexTreeLinguist.allocate(
at edu.cmu.sphinx.decoder.AbstractDecoder.allocate(
at edu.cmu.sphinx.recognizer.Recognizer.allocate(
at edu.cmu.sphinx.api.StreamSpeechRecognizer.startRecognition(
at edu.cmu.sphinx.api.StreamSpeechRecognizer.startRecognition(
at com.questico.qta.RTP$

The LM file exists. We tried the LM from within the Voxforge Package (converted it with sphinx_lm_convert to BIN-format). We also generated a new LM using Gooofy (, with the same result.
Does anybody know what we should consider as the reason for this? All other Models work perfectly with AND without grammar (en-us-8khz from CMUSphinx, self-trained Spanish Voxforge model, too.)
Thanks for your help.

--- (Edited on 7/22/2016 8:59 am [GMT-0500] by Pacer) ---