Slovak Broadcast News Speech Recognition and Transcription System

We have developed a working prototype of automatic subtitling system for transcription, archiving, and indexing of Slovak audiovisual recordings, such as lectures, talks, discussions or broadcast news. To go further in the development and research, we had to incorporate more and more modern speech technologies and embrace nowadays deep learning techniques. This paper describes transition and changes made to our working prototype regarding speech recognition core replacement, architecture changes and new web-based user interface. We have used the state-of-the art speech toolkit KALDI and distributed architecture to achieve better responsivity of the interface and faster processing of the audiovisual recordings. Using acoustic models based on time delay deep neural networks we have been able to lower the system’s average word error rate from previously reported 24% to 15%, absolutely.