Concerned with the difficulty of pupils with visual impairments in doing experiments in Physics, a group of students from the Faculty of Physics, University of  Science and  Education (UED) - the University of Da Nang (UD) has created a device that can emit easy-to-hear sound and gives highly accurate results in experiments.

Once Student Tran Thi Thanh Nhan, leader of the research team, volunteered to teach Physics at Nguyen Dinh Chieu High School, she realized that it is very difficult for blind children when attending the class to verify the law of light refraction and geometrical optics because there is no alternative but to observe the experiment.

At that time, Nhan thought that if she had the opportunity, she would make a sound-emitting device for them to visualize easily, understand more deeply about the lesson, and create excitement in learning. Later, her research team finally completed the device and donated it to Nguyen Dinh Chieu Special School so that the students could have better experimental lessons.

“The device is like a round box designed to be compact but integrated with numerous attributes inside. The device structure includes a laser signal generator, signal receiver, degree ruler, and sound generator.Based on the theory of light refraction and the design model, we have made the code to make the sound of the angle measurement, assembled and manufactured a complete device," analysed student Dang Thi Ngoc Huyen, a member of the research team.

To perform experiments related to the phenomenon of light refraction, the experimental set needs a light source, mica semi-cylindrical block, signal generator, and protractor receiver. The light source must be able to produce monochromatic and clear light rays with moderate light intensity, causing no harm to students.

The light ray hitting the centre of the ruler lying on the plane of the protractor is a red laser. Angle measurement sounds are clear and loud enough. Also, parts of the device are in Braille so students can easily locate them.

Students adjust the angle of incidence by moving the laser transmitter, and they modify the receiver to receive the refracted ray after hearing the signal to measure the angle of incidence. At the correct position of the refracted ray, the device will automatically emit an angle measurement sound. Then the experimenter listens to the alarm, records the angles, and finally tests the law by scaling the formula.

In addition, with the aim of assisting the visually impaired pupils and teacher in use and guidance easily, the team created a guidebook outlining the steps to conduct the experiment in bilingual, lowercase and braille for visually impaired children. Therefore, they can be able to measure and understand the path of light rays in a number of optical experiments using a combination of the device and the book.

According to Dr Le Thanh Huy, lecturer at the Department of Physics, the UED-the UD, schools for disabled pupils have needed more research on teaching equipment to help students with disabilities learn all subjects well in general and Physics in particular. The project of a group of students from the Faculty won the third prize in the Science Research Student Competition in Da Nang City in 2021, propelling the group to continue to come up with new ideas.

“In the coming time, we will promote research with the hope that teaching equipment will be available in most specialized schools, thereby spreading the spirit to pedagogical students throughout the country as well as other academic institutions to conduct research on teaching products for students with disabilities”, said Dr Le Thanh Huy.

Reporting by HUYNH TUONG VY- Translating by T.VY