Master's Thesis

Language Modeling for Spech Recognition in Czech

Final Thesis 443.16 kB

Author of thesis: Ing. Tomáš Mikolov, Ph.D.

Acad. year: 2006/2007

Supervisor: doc. RNDr. Pavel Smrž, Ph.D.

Reviewer: prof. Dr. Ing. Jan Černocký

Abstract:

This work concerns the problematic of language modeling in automatic speech recognition. Currently widely used techniques for advanced language modeling based on statistical approach are described in the first part of work - class based language models, factored language models and neural network based language models. In the next section, implementation of neural network based language model is described. Results obtained on "Pražský mluvený korpus" and "Brněnský mluvený korpus" corpora (1 170 000 words) are reported, with perplexity reduction around 20%. Also, results obtained after rescoring N-best lists with spontaneous speech are reported, with absolute improvement in accuracy by more than 1%. In the conclusion, possible uses of the work are mentioned, along with possible extensions in the future. Finally, main weaknesses of current statistical language modeling techniques are described.

Keywords:

language modeling, Czech language, n-gram statistics, neural networks, speech recognition, artificial intelligence

Date of defence

21.06.2007

Result of the defence

Defended (thesis was successfully defended)

znamkaAznamka

Grading

A

Language of thesis

Czech

Faculty

Department

Study programme

Information Technology (IT-MSC-2)

Field of study

Computer Graphics and Multimedia (MGM)

Supervisor’s report
doc. RNDr. Pavel Smrž, Ph.D.

Grade proposed by supervisor: B

Reviewer’s report
prof. Dr. Ing. Jan Černocký

Grade proposed by reviewer: B

Responsibility: Mgr. et Mgr. Hana Odstrčilová