An Automatically Aligned Corpus of Child-directed Speech

Forced alignment would enable phonetic analyses of child directed speech (CDS) corpora which have existing transcriptions. But existing alignment systems arc inaccurate due to the atypical phonetics of CDS. We adapt a Kaldi forced alignment system to CDS by extending the dictionary and providing it with heuristically-derived hints for vowel locations. Using this system, we present a new time-aligned CDS corpus with a million aligned segments. We manually correct a subset of the corpus and demonstrate that our system is 70% accurate. Both our automatic and manually corrected alignments are publically available at osf. io/ke44q.