ARL STEP Example Panels
The following are screenshots of the STEP trail panels that a user would see when taking a test using the various methodologies. See the STEP User Manual for a much more thorough discussion of STEP functionality.
ITU-R Recommendation BS.1116
ITU-R Recommendation BS. 1116, "Methods for the subjective assessment of small impairments in audio systems including multichannel sound systems" is appropriate for assessing the quality of systems that are nearly transparent
ITU-R Recommendation BS.1534
ITU-R Recommendation BS.1534, "MUlti-Stimulus test with Hidden Reference and Anchor (MUSHRA)" is appropriate for assessing the quality of systems with moderate impairments.
Two-comparison forced-choice
Two-comparison forced-choice methodology assesses the relative quality of two systems and is the test most able to discriminate small differences in quality. The test can be run using either 5-point or 7-point grading scales
A/B/X tests
A two-comparison forced-choice A/B/X test determines whether (or not) two systems are judged to have the same quality.
Training
The training panel can be used by a test administrator to demonstrate audio impairments.
It can also be used by audio codec developers. training panel can be used to get a quick assessment of the quality impact of varying one or more coder parameters (where each parameter variation is a different "system under test").
