Speaker recognition over VoIP network

Abstract

This thesis deals with the Automatic Speaker Recognition (ASR) system over narrowband Voice over Internet Protocol (VoIP) networks. There are several artifacts of VoIP network such as speech codec, packet loss and packet re-ordering, network jitter & echo. In this thesis, packet loss is considered as the research issue in order to investigate performance degradation for an ASR system, due to packet loss. As the voice packets travel over Internet Protocol (IP) network, they tend to take different routes. Some of them are dropped by the channel due to congestion and some are rejected by the receiver. This packet loss reduces the perceptual quality of speech. Therefore, it is natural to expect that packet loss may affects the performance of an ASR system. To alleviate this degradation in ASR system performance due to packet loss, novel interleaving schemes and lossy training method are proposed. It is shown in the present work that these interleaving schemes and lossy training methods significantly help in improving the performance of an ASR system.