There are 25 million people in the world who are visually impaired, and the number is increasing at a rate of 5 people per minute. People who have poor visual perception usually develop a better auditory sense. Using updated understanding of neural plasticity, we see a great potential for the visually impaired in learning a new navigation way by using the electronic echolocation mimicking the bat.

In the wild nature, bats are born partially blind. However, this does not have any impact on their survival. They can survive in the dark with ultrasound sensitive ears assimilating innovative radar, ultrasound measurement and search techniques. “Bat Ears” is a new echo-location device developed by Hong Kong Polytechnic University which employs the unique characteristic of ultrasound. The bouncing signal of the ultrasound will be translated into a low frequency sound which a normal person can hear and bear. Subjects are able to generate a mental image of the surrounding after receiving short training. The ultimate goal of “Bat Ears” is to provide an effective navigation system similar to that of a bat for visually impaired persons.