Seeing Through Sound

Sensory substitution device helps legally blind patients see through sound

(RxWiki News) A small trial has revealed that sound aids may be helpful in training blind individuals to actually "view," or recognize faces and facial expressions, read words and identify images.

Congenitally blind participants that utilized a sensory substitution device were able to gain enough sight to be considered low-vision sighted.

"Get regular eye exams to identify vision loss early."

Amir Amedi, PhD, of the Edmond and Lily Safra Center for Brain Sciences and the Institute for Medical Research Israel-Canada at the Hebrew University, showed patients how to use the device called "The vOICe," which converts images from a miniature camera into soundscapes using a predictive algorithm.

This allows individuals to interpret visual information by listening to sounds emitted from the camera.

During the study, eight blind participants were briefly trained to use the device in a lab, where they learned how to identify everyday objects, locate people and identify their postures and facial expressions and read letters and words.

They were later asked to identify letters on an eye chart during a conventional eye exam.

The group averaged a vision level of 20/360. Though this was not anywhere close to normal vision of 20/20, it was better than the World Health Organization's 20/400 criteria for blindness.

All of the participants scored well enough to fall into a category called low-vision sighted instead of being considered blind.

This was significant because many blind individuals may not be candidates for sight-restoring operations such as a prosthetic retina. In addition, such procedures can be expensive and may not be available to many patients who do qualify.

Researchers said this makes less expensive and non-invasive sensory substitution devices attractive alternatives. They indicated that the devices could easily be made available to the 39 million blind individuals worldwide, particularly those in developing countries, allowing them to "see" in high resolution through sound.

The study was recently published in journal PLoS One.

Review Date: 
May 17, 2012