Podcastle: collaborative training of acoustic models on the basis of wisdom of crowds for podcast transcription

This paper presents acoustic-model-training techniques for improving automatic transcription of podcasts. A typical approach for acoustic modeling is to create a task-specific corpus including hundreds (or even thousands) of hours of speech data and their accurate transcriptions. This approach, however, is impractical in podcast-transcription task because manual generation of the transcriptions of the large amounts of speech covering all the various types of podcast contents will be too costly and time consuming. To solve this problem, we introduce collaborative training of acoustic models on the basis of wisdom of crowds, i.e., the transcriptions of podcast-speech data are generated by anonymous users on our web service PodCastle. We then describe a podcast-dependent acoustic modeling system by using RSS metadata to deal with the differences of acoustic conditions in podcast speech data. From our experimental results on actual podcast speech data, the effectiveness of the proposed acoustic model training was confirmed.