Improving Factored Hybrid HMM Acoustic Modeling without State Tying

@inproceedings{Raissi2022ImprovingFH,
  title={Improving Factored Hybrid HMM Acoustic Modeling without State Tying},
  author={Tina Raissi and Eugen Beck and Ralf Schl{\"u}ter and Hermann Ney},
  booktitle={ICASSP},
  year={2022}
}
In this work, we show that a factored hybrid hidden Markov model (FH-HMM) which is defined without any phonetic state-tying outperforms a state-of-the-art hybrid HMM. The factored hybrid HMM provides a link to transducer models in the way it models phonetic (label) context while preserving the strict separation of acoustic and language model of the hybrid HMM approach. Furthermore, we show that the factored hybrid model can be trained from scratch without using phonetic state-tying in any of… 

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