Specialized acoustic models for hyperarticulated speech

This study aims to improve the performance of automatic speech recognizers at hyperarticulated speech. Hyperarticulation often occur as a strategy to recover previous recognition errors in spoken dialogue systems. Contrary to this intention a significant performance degradation can be observed at hyperarticulation. In this paper we present an analysis of features that caused the performance loss. The average phone duration is nearby 20% longer. Pitch contour and fundamental frequency change significantly at hyperarticulation. We report on adapting acoustic and transition models to hyperarticulated speech. We achieved a word error reduction about 23% at hyperarticulation.