A Color-to-Speech Sensory Substitution Device for the Visually Impaired

A hardware device is presented that converts color to speech for use by the blind and visually impaired. The use of audio tones for transferring knowledge of colors identified to individuals was investigated but was discarded in favor of the use of direct speech. A unique color-clustering algorithm was implemented using a hardware description language (VHDL), which in-turn was used to program an Altera Corporation’s programmable logic device (PLD). The PLD maps all possible incoming colors into one of 24 color names, and outputs an address to a speech device, which in-turn plays back one of 24 voice recorded color names. To the author’s knowledge, there are only two such color to speech systems available on the market. However, both are designed to operate at a distance of less than an inch from the surface whose color is to be checked. The device presented here uses original front-end optics to increase the range of operation from less than an inch to sixteen feet and greater. Because of the increased range of operation, the device can not only be used for color identification, but also as a navigation aid.