Saad Bhamla, an undergraduate in Mumbai, India, has invented a do-it-yourself hearing aid made from inexpensive, easy-to-find parts. “At bulk rates, Bhamla says, it would cost just under $1 to make,” reports Science Magazine. “But anyone with the freely available blueprints and a soldering iron can make their own for not much more — maybe $15 or $20, Bhamla says.” From the report: Inspired by his grandparents and a hearing-impaired colleague — who is the first author on the new paper — Bhamla and his team set out to develop a cheap hearing aid built with off-the-shelf parts. They soldered a microphone onto a small circuit board to capture nearby sound and added an amplifier and a frequency filter to specifically increase the volume of high-pitch sounds above 1000 hertz. Then they added a volume control, an on/off switch, and an audio jack for plugging in standard earphones, as well as a battery holder. The device, dubbed LoCHAid, is the size of a matchbox and can be worn like a necklace.
Next, Bhamla and his colleagues tested the device. They found that it boosted the volume of high-pitch sounds by 15 decibels while preserving volumes at lower pitches. It also filtered out interference and sudden, loud sounds like dog barks and car horns. Finally, tests with an artificial ear revealed that LoCHAid might improve speech recognition, by bringing conversations closer to the quality heard by healthy individuals. It complied with five out of six of the World Health Organization’s preferred product recommendations for hearing aids, the researchers report today in PLOS ONE. There are some drawbacks. The device can’t be fine-tuned for individual needs, and the researchers anticipate that LoCHAid’s parts will wear out after about a year and a half. It’s also bulky, though a smaller version is in development.
Bhamla notes that it needs to be clinically tested before his device can be sold as a “hearing aid” in the United States.
Read more of this story at Slashdot.