Speech Coding pp 117-120 | Cite as

Signal Gain and Harmonics to Noise Ratio

  • Tom BäckströmEmail author
Part of the Signals and Communication Technology book series (SCT)


The final basic component of the speech source model is that of the intensity, volume or energy of the two main components, voiced and unvoiced parts of the speech signal. Usually, signal output energy is modelled by simple gain factors applied to the excitations of the filters. The two parts, unvoiced excitation corresponding to the residual codebook and the voiced excitation corresponding to the adaptive codebook, are most commonly multiplied with two scalar gain factors which are coded jointly. Alternatively, it is possible to encode a single output-energy gain and steer the proportion of components with a ratio-factor corresponding to the harmonics to noise ratio (HNR).


Output Energy Vector Quantisation Perceptual Model Speech Production Model Joint Gain 
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  1. 1.
    3GPP. TS 26.445, EVS Codec Detailed Algorithmic Description; 3GPP Technical Specification (Release 12) (2014)Google Scholar

Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  1. 1.International Audio Laboratories Erlangen (AudioLabs)Friedrich-Alexander University Erlangen-Nürnberg (FAU)ErlangenGermany

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