Absolute Category Rating
The Absolute Category Ranking method allows the participants to evaluate the perception of sounds over a reference fixed-level category scale.
In the Absolute Category Rating method, several sounds are presented to each listener who has to rate each of them with respect to a specific question. For example, Evaluate the acoustic comfort in this situation and rate it on the given opinion scale. This psychophysics method uses a predefined scale, usually made of five ordered levels. For example, when dealing with the perception of quality, the following scale is used:
Excellent
Good
Fair
Poor
Bad
Note: Sounds are presented in a random order to each listener and can be repeated once or several times. Repeated sounds are never presented directly after their first presentations.Note: For more information, see ACR standard, Mean Opinion Score (MOS) terminology standard and the Statistics and Figures.
Listening test
Each listener has to:
Listen to each presented sound.
Assess its quality on the ACR scale.
Validate the evaluation.
Note: A Listener cannot validate before having listened to the sound entirely, and before having changed the default rating at least once. For more information, see the Setup instructions on the General Conduction parameters.