DSPRelated.com
Towards Efficient and Robust  Automatic Speech Recognition:  Decoding Techniques and  Discriminative Training

Towards Efficient and Robust Automatic Speech Recognition: Decoding Techniques and Discriminative Training

Janne Pylkkönen
Still RelevantAdvanced

Automatic speech recognition has been widely studied and is already being applied in everyday use. Nevertheless, the recognition performance is still a bottleneck in many practical applications of large vocabulary continuous speech recognition. Either the recognition speed is not sufficient, or the errors in the recognition result limit the applications. This thesis studies two aspects of speech recognition, decoding and training of acoustic models, to improve speech recognition performance in different conditions.


Summary

This PhD thesis investigates decoding strategies and discriminative training methods to improve the speed and accuracy of large-vocabulary continuous speech recognition systems. It explains practical trade-offs in decoder design, search/pruning techniques, and sequence-level discriminative training for acoustic models, with guidance on improving robustness in varied conditions.

Key Takeaways

  • Apply sequence-discriminative training to acoustic models to reduce recognition errors compared with purely maximum-likelihood methods.
  • Tune decoding parameters (beam width, pruning thresholds, insertion penalties) to balance recognition speed and search errors.
  • Use lattice generation and rescoring strategies to enable efficient post-decoding model improvements without full re-decoding.
  • Combine robust feature processing with discriminative criteria to improve ASR performance in noisy or mismatched environments.

Who Should Read This

Advanced researchers and engineers in speech and audio processing or machine learning working on acoustic modeling, decoder implementation, or system-level ASR performance optimization.

Still RelevantAdvanced

Topics

Audio ProcessingMachine LearningStatistical Signal ProcessingFFT/Spectral Analysis

Related Documents