Syntactic reanalysis in language models for speech recognition

• Published in: 2017 Joint IEEE International Conference on Development and Learning and Epigenetic Robotics (ICDL-EpiRob) pp. 215 - 220
• Main Authors: Twiefel, Johannes, Hinaut, Xavier, Wermter, Stefan
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.09.2017
• Subjects: Acoustics; Data models; Google; Grammar; Hidden Markov models; Speech; Speech recognition
• ISSN: 2161-9484
• DOI: 10.1109/DEVLRN.2017.8329810

State-of-the-art speech recognition systems steadily increase their performance using different variants of deep neural networks and postprocess the results by employing N-gram statistical models trained on a large amount of data coming from the general-purpose domain. While achieving an excellent performance regarding Word Error Rate (17.343% on our HumanRobot Interaction data set), state-of-the-art systems generate hypotheses that are grammatically incorrect in 57.316% of the cases. Moreover, if employed in a restricted domain (e.g. HumanRobot Interaction), around 50% of the hypotheses contain out-of-domain words. The latter are confused with similarly pronounced in-domain words and cannot be interpreted by a domain-specific inference system. The state-of-the-art speech recognition systems lack a mechanism that addresses the syntactic correctness of hypotheses. We propose a system that can detect and repair grammatically incorrect or infrequent sentence forms. It is inspired by a computational neuroscience model that we developed previously. The current system is still a proof-of-concept version of a future neurobiologically more plausible neural network model. Hence, the resulting system postprocesses sentence hypotheses of state-of-the-art speech recognition systems, producing in-domain words in 100% of the cases, syntactically and grammatically correct hypotheses in 90.319% of the cases. Moreover, it reduces the Word Error Rate to 11.038%.