$1 hearing aid

When Saad Bhamla was studying as an undergraduate in Mumbai, India, he wanted to give his maternal grandparents a gift: a pair of hearing aid. It turned out that the price of hearing aids was so high that it was far beyond his ability. Today, 15 years later, Bamra, an assistant professor of chemical and molecular bioengineering at the Georgia Institute of Technology, has invented a cheap hearing aid for the world's old man. It could help millions of people with age-related hearing loss and cost as little as a drink.

Frank Lin who is an otolaryngologist from the Johns Hopkins Cochlear and Public Health Centre, said the new device was “expectable.”

There are 230 million people aged 65 and over suffering from hearing loss globally. In general, it is difficult to distinguish high-pitched sounds, such as electronic beeps and speech sounds. As a result, their own words are unclear, and their cognitive ability declines.

Many elderly people use hearing aids. A customized hearing aid amplifies sound at a precise frequency that the listener cannot hear. Georgia Tech's Bamra, who specializes in “cheap devices”, said at nearly $5,000 per pair, a slightly better hearing aid is a true “luxury” for low- and middle-income countries. Low-end hearing aids are cheap, but not customized, and still cost as much as $500. They are like “cheap headphones on a plane”.

To fulfill that dream, Bamra and her team get down to develop a cheap hearing aid, using only existing parts. They soldered microphones onto small circuit boards to capture sounds around, and added an amplifier and a frequency filter, especially to raise the volume of high-pitched sounds above 1,000 Hertz. Then, they installed volume controls, on/off keys, frequency sockets for plugging in standard earphones, and battery holders.