The concept is that the device uses three CdS photo cells, each with its own color filter. Red, green and blue will be used for the filters.
There are three audio oscillators running continually at different preset frequencies .
The volume level from each oscillator is controlled by one of the filtered CdS cells and that signal is fed to a audio amplifier.
The end user will hear a chord of up to three tones with variable levels so that the user should be able to determine the scanned color based on the combination of tones and levels.
For training purposes, a wide range of color samples with braille and text labels will be provided.