Institute for Telecommunication Sciences
the research laboratory of the National Telecommunications and Information Administration

S. Voran

Abstract: ITU-T Recommendation P.861 describes an objective speech quality assessment algorithm for speech codecs. This algorithm transforms codec input and output speech signals into a perceptual domain, compares them, and generates a noise disturbance value, which can be used to estimate perceived speech quality. The performance of this algorithm can be judged by the correlation between those estimates and actual listener opinions from formal subjective listening tests. We show that significant simplifications can be made to the P.861 algorithm with very minimal effect on its performance. Specifically, for the portions of the algorithm under study here, 64% of the floating point operations can be eliminated with only a 3.5% decrease in average correlation to listener opinions. The resulting simplified algorithm may offer a practical new objective function to drive parameter selections, excitation searches, and bit-allocations in speech and audio coders.

Keywords: telephony; band pass filters; acoustic noise; auditory system; Filtering algorithms; frequency response; Laplace equations; Neodymium; speech codecs; working environment noise


To request a reprint of this report, contact:

Lilli Segre, Publications Officer
Institute for Telecommunication Sciences
(303) 497-3572
LSegre@ntia.gov

For technical information concerning this report, contact:

Stephen D. Voran
Institute for Telecommunication Sciences
(303) 497-3839
svoran@ntia.doc.gov


Disclaimer: Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.

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