Speech Coding at low and very low bit rate has become the paramount importance in accommodating the tremendous increase in the number of users in the presence of constraints of bandwidth and power in such areas as cellular radio, GSM or satellite links. The paper will cover important areas in Speech Coding. First part is concerned with an overview of the speech production model. The second part...

Neural audio/speech coding has recently demonstrated its capability to deliver high quality at much lower bitrates than traditional methods. However, existing neural codecs employ either acoustic features or learned blind with a convolutional network for encoding, by which there are still temporal redundancies within encoded features. This paper introduces latent-domain predictive into the VQ-V...

A transform coding method for coding higher layers of a multi-layer embedded speech and audio coding system using factorial pulse codebook is proposed. The proposed methods use frequency selective attenuation of lower layer output to reduce the spurious noise generated when speech model based coding method is used in lower layers for coding of the nonspeech signals. The frequency selective atte...

The influence of encoding and decoding speech on automatic speech recognition is investigated in this paper with respect to applications in today’s telecommunication networks. The deterioration of recognition performance is presented for several coding schemes in GSM and future mobile networks. The extraction of acoustic features for the recognition is done with the already standardized ETSI fr...