An Embedded Variable Bit-Rate Audio Coder for Ubiquitous Speech Communications

  • Do Young Kim
  • Jong Won Park
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4412)


In this paper, we propose an embedded variable bit-rate (VBR) audio coder to provide the fittest quality of service (QoS) and better connectivity of service for the ubiquitous speech communications. It has scalable bandwidth for narrowband to wideband speech signal, and embedded 8 32 kbit/s VBR corresponding to the network condition and terminal capacity. For the design of the embedded VBR coder, the narrowband signals are compressed by an existing standard speech coding method for the compatibility with G.729 coder, and then the other signals are compressed hierarchically on the basis of CELP enhancement and transform coding with temporal noise shaping (TNS) method. By the objective and subjective quality tests, it is shown that the proposed embedded VBR audio coder provides a reasonable quality compared with existing audio coders such as G.722 and G.722.2 in terms of mean opinion score (MOS) and perceptual evaluation of speech quality of wideband (PESQ-WB).


Embedded Coder G.729EV MOS PESQ-WB Scalable Audio Coder Ubiquitous Audio 


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Copyright information

© Springer Berlin Heidelberg 2007

Authors and Affiliations

  • Do Young Kim
    • 1
  • Jong Won Park
    • 2
  1. 1.Multimedia Communications Team, Electronics and Telecommunications Research Institute, 161 Gajeong-Dong, Yuseong-Gu, Daejeon, 305-700Rep. of Korea
  2. 2.Department of Information Communications Engineering, Chungnam National University, 220 Gung-Dong, Yuseong-Gu, Daejeon, 305-764Rep. of Korea

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