DTW-based phonetic alignment using multiple acoustic features

This paper presents the results of our effort in improving the accuracy of a DTW-based automatic phonetic aligner. The adopted model assumes that the phonetic segment sequence is already known and so the goal is only to align the spoken utterance with a reference synthetic signal produced by waveform concatenation without prosodic modifications. Instead of using a single acoustic measure to compute the alignment cost function, our strategy uses a combination of acoustic features depending on the pair of phonetic segment classes being aligned. The results show that this strategy considerably reduces the segment boundary location errors, even when aligning synthetic and natural speech signals of different gender speakers.