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Acoustic model in Sphinx 4
User: ahmad92hassan
Date: 1/21/2009 11:23 pm
Views: 8152
Rating: 15

ncst is packege like an4

This is the error thats come at the time of decoding

Building task ncst 
Task not previously defined. User has to provide language model and supporting variables

Re: Acoustic model in Sphinx 4
User: kmaclean
Date: 1/26/2009 10:13 am
Views: 1075
Rating: 15

Hi ahmad92hassan,

>User has to provide language model and supporting variables

I am assuming this is still part of same thread you start...

I believe that Sphinx requires a language model (in addition to the acoustic model you already created using your ncst speech corpus).  From this Sphinx FAQ:

What is a Language Model (LM) file?

An LM file (often with a .lm extension) is a Language model. The language model describes the likelihood, probability, or penalty taken when a sequence or collection of words is seen. Sphinx2 uses N-gram models, and usually N is 3, so they are trigram models, and these are sequences of three words. All the sequences of three words, two words, and one word are combined together using back-off weights in order to assign probabilities to sequences of words.

Many of the advances in accuracy in speech recognition have come from language modeling. Having a language model that is tuned to a particular application, especially when it is a small language, leads to much better results than when the language model is mismatched to the one given. You can see this if you run the "turtle" demo, which is made from sentences like "rotate right forty five degrees" and "go forward ten meters," and then start reading Alice in Wonderland. The system will do the best it can to fit Alice into the the toy vocabulary and language model.

There are two recommended ways to build a language model at the moment: using the web-based Language Modelling Tool (LMtool), where you simply upload a set of sentences and it creates everything you need, or by the more elaborate, but more powerful CMU/Cambridge Statistical Language Modeling Toolkit .

There are also some example language models, including a class language model.

I am not sure what the supporting variables are, but the Sphinx docs should be able to tell you,


Re: Acoustic model in Sphinx 4
User: Wedyan
Date: 10/18/2011 1:48 pm
Views: 2562
Rating: 12

I have the same error but the language modle file is exist !