Noise post processing based on a stationary noise generator

H. Ehara, K. Yasunaga, Y. Hiwasaki, Kazunori Mano

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The paper presents a newly developed noise post-processing (NPP) algorithm for improving subjective performance of low bit-rate code excited linear prediction (CELP) decoding. The algorithm is based on a stationary noise generator and improves subjective quality of a noisy signal input. A backward adaptive detector defines noisy input signal segments from decoded line spectral frequency (LSF), energy, and pitch parameters. By using LSF and energy parameters from the past, the noise generator estimates and produces stationary noise. The algorithm is independent of the main codec algorithm and is applicable to any CELP decoder. When applied to G.729 and G.723.1, our test results show that the algorithm improves subjective performance at around 0.2-0.8 in degradation category rating (DCR) mean opinion score (DMOS) under several background noise conditions.

Original languageEnglish
Title of host publication2002 IEEE Speech Coding Workshop: A Paradigm Shift Toward New Coding Functions for the Broadband Age, SCW 2002 - Proceedings
PublisherInstitute of Electrical and Electronics Engineers Inc.
Number of pages3
ISBN (Print)0780375491, 9780780375499
Publication statusPublished - 2002
Externally publishedYes
EventIEEE Speech Coding Workshop, SCW 2002 - Tsukuba City, Ibaraki, Japan
Duration: 2002 Oct 62002 Oct 9


OtherIEEE Speech Coding Workshop, SCW 2002
CityTsukuba City, Ibaraki

ASJC Scopus subject areas

  • Linguistics and Language
  • Computer Vision and Pattern Recognition
  • Human-Computer Interaction
  • Software
  • Language and Linguistics


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