Visual representations of data are commonly used to communicate research results. However, such representations might introduce several possible challenges for the human visual perception system, for example in perceiving brightness levels. Sonification, adding sound to the visual representation, might be used to overcome these challenges. As sonification provides additional information, sonification could be useful in supporting interpretations of a visual perception. In the present study, usefulness in terms of accuracy of sonification was investigated with an interactive sonification test. In the experiment, participants were asked to identify the highest brightness level in a monochrome visual representation. The task was performed in four conditions, one with no sonification and three with different sonification settings. The results show that sonification is useful, as measured by higher task accuracy.