Julius: two-pass large vocabulary continuous speech recognition (LVCSR) decoder software

Links

• Julius on sourceforge

"Julius" is a high-performance, two-pass large vocabulary continuous speech recognition (LVCSR) decoder software for speech-related researchers and developers. Based on word N-gram and context-dependent HMM, it can perform almost real-time decoding on most current PCs in 60k word dictation task. Major search techniques are fully incorporated such as tree lexicon, N-gram factoring, cross-word context dependency handling, enveloped beam search, Gaussian pruning, Gaussian selection, etc. Besides search efficiency, it is also modularized carefully to be independent from model structures, and various HMM types are supported such as shared-state triphones and tied-mixture models, with any number of mixtures, states, or phones. Standard formats are adopted to cope with other free modeling toolkit such as HTK, CMU-Cam SLM toolkit, etc.

Originally done for Japanese.

Here you can get Japanese and English free language/acoustic models.

• Japanese

   

  • Japanese language model (20k-word trained by newspaper article) and acoustic models (Phonetic tied-mixture triphone / monophone)

  More various types of Japanese N-gram LM and acoustic models are available at CSRC. For more detail, please contact csrc@astem.or.jp.

• English

   

  • We currently have a sample English acoustic model trained from the WSJ database. According to the license of the database, this model *cannot* be used to develop or test products for commercialization, nor can they use it in any commercial product or for any commercial purpose. Also, the performance is not so good. Please contact to us for further information.
  • The VoxForge-project is working on the creation of an open-source acoustic model for the English language.