Language model adaptation for lecture transcription by document retrieval

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-13623-3_14 With the spread of MOOCs and video lecture repositories it is more important than ever to have accurate methods for automatically transcribing video lectures. In this work, we propose a simple yet effective language model adaptation technique based on document retrieval from the web. This technique is combined with slide adaptation, and compared against a strong baseline language model and a stronger slide-adapted baseline. These adaptation techniques are compared within two different acoustic models: a standard HMM model and the CD-DNN-HMM model. The proposed method obtains improvements on WER of up to 14% relative with respect to a competitive baseline as well as outperforming slide adaptation. The research leading to these results has received fund-ing from the European Union Seventh Framework Programme (FP7/2007-2013)under grant agreement no 287755 (transLectures) and ICT Policy Support Pro-gramme (ICT PSP/2007-2013) as part of the Competitiveness and Innovation Framework Programme (CIP) under grant agreement no 621030 (EMMA), the Spanish MINECO Active2Trans (TIN2012-31723) research project and the Spanish Government with the FPU scholarships FPU13/06241 and AP2010-4349. Martínez-Villaronga, A.; Del Agua Teba, MA.; Silvestre Cerdà, JA.; Andrés Ferrer, J.; Juan, A. (2014). Language model adaptation for lecture transcription by document retrieval. En Advances in Speech and Language Technologies for Iberian Languages. Springer Verlag (Germany). 129-137. https://doi.org/10.1007/978-3-319-13623-3_14 coursera.org: Take the World’s Best Courses, Online, For Free, http://www.coursera.org/ poliMedia: Videolectures from the “Universitat Politècnica de València, http://polimedia.upv.es/catalogo/ SuperLectures: We take full care of your event video recordings, http://www.superlectures.com transLectures, https://translectures.eu/ transLectures-UPV Toolkit (TLK) for Automatic Speech Recognition, http://translectures.eu/tlk Udacity: Learn, Think, Do, http://www.udacity.com/ Videolectures.NET: Exchange Ideas and Share Knowledge, http://www.videolectures.net/ del-Agua, M.A., Giménez, A., Serrano, N., Andrés-Ferrer, J., Civera, J., Sanchis, A., Juan, A.: The translectures-UPV toolkit. In: Navarro Mesa, J.L., Giménez, A.O., Teixeira, A. (eds.) IberSPEECH 2014. LNCS (LNAI), vol. 8854, pp. 269–278. Springer, Heidelberg (2014) Chang, P.C., Shan Lee, L.: Improved language model