Speech coding techniques and challenges: a comprehensive literature survey

Speech coding is the process of compressing speech signals for transmission and storage in communication systems. In recent years, speech coding has become increasingly important due to the growing demand for low bitrate communication systems. This paper presents a comprehensive literature survey of speech coding techniques, their importance, and the challenges associated with their implementation. We also discuss the use of speech enhancement techniques in speech coding. The survey covers various speech coding techniques and their limitations in adverse conditions. We highlight the potential of machine learning-based methods in improving speech quality and intelligibility in speech coding systems. Further, metrics for evaluating the performance of speech coding algorithms are highlighted. The survey also discusses the key issues and challenges associated with speech coding, including the trade-off between speech quality and bit rate, and the impact of background noise on speech quality. Further it also covers popular speech databases used in coding research. Our findings provide valuable insights for researchers and practitioners working in speech coding and demonstrate the importance of speech enhancement techniques for improving speech quality and intelligibility in low bitrate communication systems.