EyeMusic Sensory Substitution Device enables the blind to 'see' colors and shapes

February 4, 2014
Top: The EyeMusic's constructed audio file preserves both spatial information and image colors. The Sensory Substitution Device resizes the image to X=40 pixels (columns) by Y=24 pixels (rows) and runs a color clustering algorithm to get a 6-color image. Middle: The 2D image's X-axis is mapped to the time domain, i.e., pixels situation on the left side of the image with sound before the ones situation on its right side, illustrated here in waveform. Bottom: The Y-axis is mapped to the frequency domain, i.e., pixels situation on the upper side of the image will sound higher in frequency while those on its lower side will sound lower in frequency, illustrated here in spectrogram representation. Credit: Restorative Neurology and Neuroscience, Abboud et al.

Using auditory or tactile stimulation, Sensory Substitution Devices (SSDs) provide representations of visual information and can help the blind "see" colors and shapes. 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.

Currently SSDs are not widely used within the blind community because they can be cumbersome and unpleasant to use. However, a team of researchers at the Hebrew University of Jerusalem have developed the EyeMusic, a novel SSD that transmits shape and color information through a composition of pleasant musical tones, or "soundscapes." A new study published in Restorative Neurology and Neuroscience reports that using the EyeMusic SSD, 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.

"This study is a demonstration of abilities showing that it is possible to encode the basic building blocks of shape using the EyeMusic," explains Prof. Amir Amedi. "Furthermore, the success in associating color to musical timbre holds promise for facilitating the representation of more complex shapes."

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. "In soundscapes generated from images," notes Prof. Amedi, "there is a tendency for adjacent frequencies to be played together. Using a semitone western scale would then generate sounds that are perceived as highly dissonant. Therefore, to generate more pleasant soundscapes, we used the pentatonic musical scale that generates less dissonance when adjacent notes are played together."

While this new study shows that the EyeMusic can enable the visually impaired to extract visual shape and color information using auditory soundscapes of objects, researchers feel that this device also holds great promise for the field of visual rehabilitation in general. By providing additional color information, the EyeMusic can help facilitate object recognition and scene segmentation, while the pleasant soundscapes offer the potential of prolonged use.

"There is evidence suggesting that the brain is organized as a task-machine and not as a sensory machine. This strengthens the view that SSDs can be useful for visual rehabilitation, and therefore we suggest that the time may be ripe for turning part of the SSD spotlight back on practical visual rehabilitation," Prof. Amedi adds. "In the future, it would be intriguing to test whether the use of naturalistic sounds, like music and human voice, can facilitate learning and brain processing relying on the developed neural networks for music and human voice processing."

Additionally, the researchers hope the EyeMusic can become a tool for future neuroscience research. "It would be intriguing to explore the plastic changes associated with learning to decode color information for auditory timbre in the congenitally blind, who never experience color in their life. The utilization of the EyeMusic and its added color information in the field of neuroscience could facilitate exploring several questions in the blind with the potential to expand our understanding of brain organization in general," concludes Prof. Amedi.

Explore further: How blind can 'read' shown in new research

More information: "EyeMusic: Introducing a "visual" colorful experience for the blind using auditory sensory substitution," by S. Abboud, S. Hanassy, S. Levy-Tzedek, S. Maidenbaum, A. Amedi. Restorative Neurology and Neuroscience, 2013. DOI: 10.3233/RNN-130338

A demonstration, "EyeMusic: Hearing colored shapes" is available from the AppStore.

Related Stories

How blind can 'read' shown in new research

May 16, 2012

A method developed at the Hebrew University of Jerusalem for training blind persons to "see" through the use of a sensory substitution device (SSD) has enabled those using the system to actually "read" an eye chart with letter ...

Recommended for you

New insights on how cocaine changes the brain

November 25, 2015

The burst of energy and hyperactivity that comes with a cocaine high is a rather accurate reflection of what's going on in the brain of its users, finds a study published November 25 in Cell Reports. Through experiments conducted ...

Can physical exercise enhance long-term memory?

November 25, 2015

Exercise can enhance the development of new brain cells in the adult brain, a process called adult neurogenesis. These newborn brain cells play an important role in learning and memory. A new study has determined that mice ...

Umbilical cells help eye's neurons connect

November 24, 2015

Cells isolated from human umbilical cord tissue have been shown to produce molecules that help retinal neurons from the eyes of rats grow, connect and survive, according to Duke University researchers working with Janssen ...

Brain connections predict how well you can pay attention

November 24, 2015

During a 1959 television appearance, Jack Kerouac was asked how long it took him to write his novel On The Road. His response – three weeks – amazed the interviewer and ignited an enduring myth that the book was composed ...

No cable spaghetti in the brain

November 24, 2015

Our brain is a mysterious machine. Billions of nerve cells are connected such that they store information as efficiently as books are stored in a well-organized library. To this date, many details remain unclear, for instance ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.