OOV-detection and channel error protection for distributed speech recognition over wireless networks
Zheng‐Hua Tan, Paul Dalsgaard, Brge Lindberg · 2003 IEEE International Conference on Acoustics, Speech, and Signal Processing, 2003. Proceedings. (ICASSP '03). · 2003
This paper presents research on two aspects of distributed speech recognition (DSR) in the presence of channel transmission errors in wireless network environments. The first is on experiments with a frame-based channel error protection scheme, where in previous research we reported results from experiments using randomly distributed bit-errors. This paper presents results from experiments using three additional, more realistic error distributions: burst-like packet loss, GSM error patterns and UMTS statistics. The second is on exploiting the knowledge about channel transmission errors for the purpose of optimising the Out-of-Vocabulary (OOV) detection. Transmission errors influence the acoustic likelihood, and therefore affect the optimal threshold setting for discrimination between In-Vocabulary (IV) words and OOV words. An OOV-detection method is proposed in which the estimated Frame-Error-Rate (FER) is used to adjust the discrimination threshold. Results from experiments are reported over a range of transmission errors.