June 25, 2018 - August 3, 2018
MERL Speech & Audio Team researcher Takaaki Hori led a team of 27 senior researchers and Ph.D. students from different organizations around the world, working on "Multi-lingual End-to-End Speech Recognition for Incomplete Data" as part of the Jelinek Memorial Summer Workshop on Speech and Language Technology (JSALT). The JSALT workshop is a renowned 6-week hands-on workshop held yearly since 1995. This year, the workshop was held at Johns Hopkins University in Baltimore from June 25 to August 3, 2018. Takaaki's team developed new methods for end-to-end Automatic Speech Recognition (ASR) with a focus on low-resource languages with limited labelled data.
End-to-end ASR can significantly reduce the burden of developing ASR systems for new languages, by eliminating the need for linguistic information such as pronunciation dictionaries. Some end-to-end systems have recently achieved performance comparable to or better than conventional systems in several tasks. However, the current model training algorithms basically require paired data, i.e., speech data and the corresponding transcription. Sufficient amount of such complete data is usually unavailable for minor languages, and creating such data sets is very expensive and time consuming.
The goal of Takaaki's team project was to expand the applicability of end-to-end models to multilingual ASR, and to develop new technology that would make it possible to build highly accurate systems even for low-resource languages without a large amount of paired data. Some major accomplishments of the team include building multi-lingual end-to-end ASR systems for 17 languages, developing novel architectures and training methods for end-to-end ASR, building end-to-end ASR-TTS (Text-to-speech) chain for unpaired data training, and developing ESPnet, an open-source end-to-end speech processing toolkit. Three papers stemming from the team's work have already been accepted to the 2018 IEEE Spoken Language Technology Workshop (SLT), with several more to be submitted to upcoming conferences.
Johns Hopkins University, Baltimore, MD