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

S. Voran

Abstract: We have designed, conducted, and analyzed a subjective speech quality experiment with unrestricted timing where subjects can vote whenever their opinions are fully formed, rather than at fixed time intervals. Analysis of the resulting listening times reveals that subjects tend to listen for a longer time before approving a recording and for a shorter time before rejecting a recording. This listening-time difference tends to increase for poorer quality systems and for more critical subjects. We present a mathematical model that reproduces these results. In addition, subjects operate more quickly as they move through the experiment.

Keywords: speech quality; listening time; subjective test


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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