“When we get farsighted in old age, we just go to the drugstore or pharmacy and buy cheap reading glasses,” says the bio-engineer from the Georgia Institute of Technology. There is no comparable offer for the most common form of age-related hearing loss.

As Bhamla 15 Years as a student wanted to finance hearing aids for his grandparents, he found that they were priceless to him. Now he’s working on a cheap model that should cost just a dollar – less than a bottle of water.

Older people can usually use high notes over 1000 Hertz – such as the sounds “s” and “th” – are more difficult to perceive. However, the hearing loss curve is not the same for everyone. A modern hearing aid is therefore geared towards all eventualities. This is not possible with Bhamla’s variant – which he does not consider to be a major problem. “If you look at the hearing loss curves of patients between 65 and 79 years ago, there are very many with a similar profile, ”he says. “Similar to glasses, we can design five or six models with different amplifications in the frequency range above 1000 Hertz.” These could be tried on and tested like reading glasses.

This post comes from the edition 12 / 2020 of the Technology Review. The booklet is from 5. 11. 2020 available in stores and directly in the heise shop. Highlights from the magazine:

There are also a number of other simplifications. The electronics in his hearing aids are housed in a 3D-printed case the size of a matchbox that can be worn around the neck. There, users can adjust the volume or switch off the device. “It is difficult for older patients to use the tiny traditional hearing aids. If your hands also tremble, the devices fall down easily and are lost. ”A microphone in the housing captures the ambient sound, and an amplifier and a frequency filter then only play the sounds above 1000 Hz louder. The sound comes into the ear through simple, wired headphones.

Ten years ago, such hearing amplifiers were afflicted with a stigma. “Today we all walk around with headphones, there is no more rejection,” says the bio-engineer. If you want to try yourself on the 30 – minute do-it-yourself, you can download the plans for free from GitHub. The price for the components is 15 to 20 dollars. With mass production and without special batteries, it could drop to a dollar.

With his colleague Soham Sinha and the audiologist Vinaya Manchaiah from Lamar University in Beaumont, Texas, Bhamla subjected the device to extensive tests: On average, it amplified the high frequencies around 15 decibels, protects against sudden, loud noises such as car horns and minimizes disturbing overtones more strongly than the World Health Organization WHO recommends for hearing aids. In total, it met five of the six WHO criteria. The team published the results in the specialist journal “Plos One” (DOI: 10. 1371 / journal.pone. 0238922) “We just couldn’t record the background humming of the board lower the recommended 32 dB, but we are still working on that, “says the bio-engineer.

The robustly designed prototype put up with twelve falls from a height of 1, 80 meters and is up to a depth of six centimeters for 15 Seconds waterproof. Overall, it lasted a year and a half. At first glance, that doesn’t sound like an impressive life expectancy. But reading glasses from the drugstore are not forever either. A new US law would allow sales without FDA approval as long as the hearing aid is not referred to as a hearing aid.

(bsc )