Statistical Feature Language Model

Colloque avec actes et comité de lecture. internationale.International audienceStatistical language models are widely used in automatic speech recognition in order to constrain the decoding of a sentence. Most of these models derive from the classical n-gram paradigm. However, the production of a word dends on a large set of linguistic features : lexical, syntactic, semantic, etc. Moreover, in some natural languages the gender and number of the left context affect the production of the next word. Therefore, it seems attractive to design a language model based on a variety of word features. We present in this paper a new statistical language model, called Statistical Feature Language Model, SFLM, based on this idea. In SFLM a word is considered as an array of linguistic features, and the model is defined in a way similar to the n-gram model. Experiments carried out for French and show an improvement in terms of perplexity and predicted words

Linguistic features modeling based on Partial New Cache

The agreement in gender and number is a critical problem in statistical language modeling. One of the main problems in the speech recognition of French language is the presence of misrecognized words due to the bad agreement (in gender and number) between words. Statistical language models do not treat this phenomena directly. This paper focuses on how to handle the issue of agreements. We introduce an original model called Features-Cache (FC) to estimate the gender and the number of the word to predict. It is a dynamic variable-length Features-Cache for which the size is determined in accordance to syntagm delimitors. This model does not need any syntactic parsing, it is used as any other statistical language model. Several models have been carried out and the best one achieves an improvement of more than 8 points in terms of perplexity

Improving language models by using distant information

International audienceThis study examines how to take originally advantage from distant information instatistical language models. We show that it is possible to use n-gram models considering histories different from those used during training. These models are called crossing context models. Our study deals with classical and distant n-gram models. A mixture of four models is proposed and evaluated. A bigram linear mixture achieves an improvement of 14% in terms of perplexity. Moreover the trigram mixture outperforms the standard trigram by 5.6%. These improvements have been obtained without complexifying standard n-gram models. The resulting mixture language model has been integrated into a speech recognition system. Its evaluation achieves a slight improvement in terms of word error rate on the data used for the francophone evaluation campaign ESTER. Finally, the impact of the proposed crossing context language models on performance is presented according to various speakers