The development of a good representation of data with an auditory display requires one to choose the type of transformation between the data and auditory information and the auditory dimension to use. There is good reason to believe that using two sound dimensions in a redundant way could enhance performance compared to using the dimensions individually (Kramer, 1996). Experiments 1 and 2 showed redundancy loss when using separable dimensions in a redundant way. Experiments 3A and 4A found that duration with pitch and rate of change in pitch appear to be integral based on the Garner task. Experiment 3B, 3C and 4B used duration and the redundant combination of duration and pitch versus rate of change in pitch for the representation of numerical values. However, there was no redundancy gain found. This result could be important for auditory display designers when deciding about auditory dimensions to use in displays.