Named after abstract painter Wassily Kandinsky, The Wassiliscope analyzes the frequency of incoming light waves and converts them to their corresponding audible frequency. Audio is then sent through a triangle wave oscillator and out to the headphones in real time allowing you to listen to color.
One key realization was that light and sound are both waves. The brain just happens to interpret these frequency ranges in different ways. Because of this, the correlation between color and sound is very direct: a mapping from one frequency to another.
This translation also helped inform the physical interface. Pointing the telescope lens and hearing the change in real time makes the relationship between light and sound tangible. Eventually, you can begin to see the color in your mind's eye without needing to look.