In a new study, researchers found a way to develop a new ultra-low-cost hearing aid that can help older people worldwide who can’t afford existing hearing aids to address their age-related hearing loss.
They achieved this by using a device that could be built with a dollar’s worth of open-source parts and a 3-D-printed case.
The ultra-low-cost proof-of-concept device known as LoCHAid is designed to be easily manufactured and repaired in locations where conventional hearing aids are priced beyond the reach of most citizens.
The minimalist device is expected to meet most of the World Health Organization’s targets for hearing aids aimed at a mild-to-moderate age-related hearing loss.
The prototypes built so far look like wearable music players instead of a traditional behind-the-ear hearing aids.
The research was conducted by a team at the Georgia Institute of Technology.
Age-related hearing loss affects more than 200 million adults over the age of 65 worldwide.
Hearing aid adoption remains relatively low, particularly in low-and-middle-income countries where fewer than 3% of adults use the devices—compared to 20% in wealthier countries.
Cost is a significant limitation, with the average hearing aid pair costing $4,700 in the United States and even low-cost personal sound amplification devices—which don’t meet the criteria for sale as hearing aids—priced at hundreds of dollars globally.
Part of the reason for the high cost is that effective hearing aids provide far more than just sound amplification.
Hearing loss tends to occur unevenly at different frequencies, so boosting all sound can actually make speech comprehension more difficult.
Because decoding speech is so complicated for the human brain, the device must also avoid distorting the sound or adding noise that could hamper the user’s ability to understand.
In the study, the team assembles a prototype LoCHAid, an ultra-low-cost hearing aid built with a 3D-printed case and components that cost less than a dollar.
They chose to focus on age-related hearing loss because older adults tend to lose hearing at higher frequencies.
Focusing on a large group with similar hearing losses simplified the design by narrowing the range of sound frequency amplification needed.
The team decided to build their device using electronic filters to shape the frequency response, a less expensive approach that was standard on hearing aids before the processors became widely available.
The electronic components of the LoCHAid cost less than a dollar if purchased in bulk, but that doesn’t include assembly or distribution costs.
Its relatively large size allows for low-tech assembly and even do-it-yourself production and repair.
The prototype uses a 3-D-printed case and is powered by common AA or lithium-ion coin-cell batteries designed to keep costs as low as possible. With its focus on older adults, the device could be sold online or over-the-counter.
The researchers have extensively studied the electroacoustic performance of their device, but the real test will come in clinical and user trials that will be necessary before it can be certified as a medical device.
The researchers are now working on a smaller version of the device that will boost the bulk component cost to seven dollars and require a sophisticated manufacturer to assemble.
One author of the study is Georgia Tech assistant professor M. Saad Bhamla.
The study is published in PLOS ONE.
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