This paper presents a preliminary study on an effective differentiable network service technique to achieve improved speech recognition under severely poor wireless channel conditions, by leveraging multiple priority levels applied to speech classes. Each speech class is assigned a different priority level based on its level of impact on speech recognition performance. Based on their priority level, frames of each speech class are given distinct levels of network quality of service (QoS) to satisfy the delay requirement and enable speech recognition at the receiver. This proposed Phone Impact (PI) based priority class is compared to the Voiced/Unvoiced (VU) based priority class in this study. The experimental results prove that the proposed scheme is effective at providing wireless network service for robust speech recognition under poor channel conditions, showing up to 2.67 dB and 5.93 dB lower Signal to Noise Ratio (SNR) operating regions compared to the VU based and plain protocols respectively. The PI based method also shows acceptable WERs at lower SNRs where VU and plain systems significantly degrade in speech recognition performance in case of retry limit of 6.
Bibliographic reference. Taufique, Azar / Vijayasankar, Kumaran / Kim, Wooil / Hansen, John H. L. / Tacca, Marco / Fumagalli, Andrea (2011): "Phone impact based speech transmission technique for reliable speech recognition in poor wireless network conditions", In INTERSPEECH-2011, 2529-2532.