$1 hearing aid

The device named LoCHAid, is the size of a matchbox and can be worn like a necklace. Bamra said, “large scaled production costs less than $1 per unit.” At the same time, someone with a little bit of electrical know-how could make the product themselves, at a total cost of $15 or $20. He said, the parts are easy to be procured and can be assembled in less than 30 minutes with a soldering iron.

During tests, they found that LoCHAid raised high-pitched sounds by 15 decibels while maintaining the volume of lower pitched sounds. It also filters out distractions and sudden loud sounds, such as dog barks and car horns. Finally, tests using artificial ears showed that conversation levels were closer to the quality of hearing in healthy individuals. The researchers reported in “PLOS ONE” yesterday, it met five of the six criteria recommended by the World Health Organization for hearing aids.

However, too simple always brings disadvantages. The device cannot be tweaked to suit individual needs or other hearing problems. Despite being waterproof and earthquake-resistant, scientists expect the LoCHAid's components to wear out in about a year and a half. Bhamla said, it is still a bit bulky and may not be portable, though smaller versions are being developed currently.

LoCHAid cannot be sold as a “hearing aid” in most countries, including the United States, until it is clinically tested. Eventually, Bhamla wants the products to be approved for sale over the counter without a prescription, as with ibuprofen or reading glasses.

The next step is to get people to use the products. According to Baram, only 3 percent of age-related hearing loss in low- and middle-income countries wear a hearing aid, while rates hover around 20 percent in countries such as the US, Britain, and Australia. In addition to the cost concerns, “many people don't realize they have a hearing impairment... And there is a social stigma associated with wearing a hearing aid.”

Lin said that if these cost-effective devices are put into use, they could benefit many people. “Theoretically, if hearing problems are alleviated, it could change cognitive pathways and reduce the risk of senile dementia.”

Baram wishes biomedical devices to be as cheap and easy to use as popular electronics. He still remembers the shock of noticing he could not afford a hearing aid. He recalled his memory, “I thought being able to afford a laptop and a mobile phone meant I could afford hearing aid, but then I realized they were ridiculously expensive. Since then, I have a better understanding of the world.”