“Cognitive psychologists have provided myriad information about the effects of sound on memory and about the effects of multiple tasks on attention. From this research, auditory graph investigators have used two principles on the impacts of using sound and vision together for graphed data. One of these principles is that adding another modality (i.e., audition to vision) will result in redundancy in the information, and thus lead to better overall comprehension of graphs. The second principle is that having two modalities will result in divided attention leading to greater cognitive load, and thus to diminished comprehension of graphs. It would be useful for auditory graph researchers to determine in which situations these two contradictory effects manifest themselves. (…)

The results suggest that processing visual and auditory graphs together is a more difficult task than processing either alone.”

Terri L. Bonebright (2005): “A SUGGESTED AGENDA FOR AUDITORY GRAPH RESEARCH”

Time is a property of the auditory system, not of the visual system. As Bertin puts it:

“La perception sonore ne dispose que de deux variables sensibles: la variation des sons et le temps.

Par contre, la perception visuelle dispose de trois variables sensibles: la variation des taches et les deux dimensions du plan, et ceci hors du temps. Les systèmes destinés à l’œil sont d’abord spatiaux et atemporels. D’où leur propriété essentielle: dans un instant de perception, les systèmes linéaires ne nous communiquent qu’un seul son ou signe, tandis que les systèmes spatiaux, dont la graphique, nous communiquent dans le même instant les relations entre trois variables.”

Jacques Bertin, Semiologie Graphique

I certainly can understand your delight in sound, but your claim that the addition of an audio encoding to a visual encoding of time-series values speeds up the process of understanding is not correct. It actually slows it down. I can see the pattern in an instant, because my brain processes the image in a parallel manner, but sounds are processed serially, which takes time. Audio encoding might be useful for people who are visually impaired, but it is not a good replacement nor even a good addition to a visual encoding in the form of a simple graph.

Stephen Few
Perceptual Edge