Abstract
When listening test subjects are required to rate changes in a single attribute, but also hear changes in other attributes, their ratings can become skewed by “dumping bias.” To assess the influence of dumping bias on timbral “clarity” ratings, listeners were asked to rate stimuli: (i) in terms of clarity only; and (ii) in terms of clarity, warmth, fullness, and brightness. Clarity ratings of type (i) showed (up to 20%) larger interquartile ranges than those of type (ii). It is concluded that in single-attribute timbral rating experiments, statistical noise—potentially resulting from dumping bias—can be reduced by allowing listeners to rate additional attributes either simultaneously or beforehand.