Audio may be new 'sight' for the blind

Researchers have developed a new Sensory Substitution Device (SSD), that transmits shape and color information through a composition of pleasant musical tones, or "soundscapes", thus helping the blind to "see" colors and shapes.

Auditory or tactile stimulation, SSDs scan images and transform the information into audio or touch signals that users are trained to understand, enabling them to recognize the image without seeing it.

However, a team of researchers at the Hebrew University of Jerusalem have developed the EyeMusic SSD, using which both blind and blindfolded sighted participants were able to correctly identify a variety of basic shapes and colors after as little as 2-3 hours of training.

Most SSDs do not have the ability to provide color information, and some of the tactile and auditory systems used are said to be unpleasant after prolonged use.

The EyeMusic, developed by senior investigator Prof. Amir Amedi, PhD, and his team at the Edmond and Lily Safra Center for Brain Sciences (ELSC) and the Institute for Medical Research Israel-Canada at the Hebrew University, scans an image and uses musical pitch to represent the location of pixels.

The higher the pixel on a vertical plane, the higher the pitch of the musical note associated with it.

Timing is used to indicate horizontal pixel location. Notes played closer to the opening cue represent the left side of the image, while notes played later in the sequence represent the right side.

Additionally, color information is conveyed by the use of different musical instruments to create the sounds: white (vocals), blue (trumpet), red (reggae organ), green (synthesized reed), yellow (violin); black is represented by silence.

In addition to successfully identifying shapes and colors, users in the new EyeMusic study indicated they found the SSD's soundscapes to be relatively pleasant and potentially tolerable for prolonged use.

The study was published in Restorative Neurology and Neuroscience.