A

HMM vs. CTC for Automatic Speech Recognition: Comparison Based on Full-Sum Training from Scratch

IEEE Spoken Language Technology Workshop (SLT), pp. 287–294

Abstract

In this work, we compare from-scratch sequence-level cross-entropy (full-sum) training of Hidden Markov Model (HMM) and Connectionist Temporal Classification (CTC) topologies for automatic speech recognition (ASR). Besides accuracy, we further analyze their capability for generating high-quality time alignment between the speech signal and the transcription, which can be crucial for many subsequent applications. Moreover, we propose several methods to improve convergence of from-scratch full-sum training by addressing the alignment modeling issue. Systematic comparison is conducted on both Switchboard and LibriSpeech corpora across CTC, posterior HMM with and w/o transition probabilities, and standard hybrid HMM. We also provide a detailed analysis of both Viterbi forced-alignment and Baum-Welch full-sum occupation probabilities.

Authors 5

  1. RWTH Aachen University

    Affiliation as printed

    RWTH Aachen University,Human Language Technology and Pattern Recognition Group,Germany

    Human Language Technology and Pattern Recognition Group, RWTH Aachen University, Germany

  2. RWTH Aachen University

    Affiliation as printed

    RWTH Aachen University,Human Language Technology and Pattern Recognition Group,Germany

    AppTek GmbH, Aachen, Germany

    Human Language Technology and Pattern Recognition Group, RWTH Aachen University, Germany

  3. RWTH Aachen University

    Affiliation as printed

    RWTH Aachen University,Human Language Technology and Pattern Recognition Group,Germany

    AppTek GmbH, Aachen, Germany

    Human Language Technology and Pattern Recognition Group, RWTH Aachen University, Germany

  4. RWTH Aachen University

    Affiliation as printed

    RWTH Aachen University,Human Language Technology and Pattern Recognition Group,Germany

    AppTek GmbH, Aachen, Germany

    Human Language Technology and Pattern Recognition Group, RWTH Aachen University, Germany

  5. RWTH Aachen University

    Affiliation as printed

    RWTH Aachen University,Human Language Technology and Pattern Recognition Group,Germany

    AppTek GmbH, Aachen, Germany

    Human Language Technology and Pattern Recognition Group, RWTH Aachen University, Germany

Cited by 12 stored of 12

12 results

No patents citing this paper on Lens.org (checked 2026-10-06).

References 36