LoCHAid: A Hearing aid that doesn’t burn a Hole in your Pocket

Sep 30, 2020

A hearing aid that costs less than a cup of coffee. Sounds too good to be true? Well, a team led by Dr. M Saad Bhamla, an assistant professor in the School of Chemical and Biomolecular Engineering at the Georgia Institute of Technology has made it possible for it to be too good and absolutely true at the same time and we’ll tell you how. The ultra-low-cost proof-of-concept device that the team has come up with is known as LoCHAid.

"The need is obvious because conventional hearing aids cost a lot and only a fraction of those who need them have access,” said Professor Bhamla, and rightly so. Statistics say that age related hearing loss plagues more than 200 million people over the age of 65 worldwide. Yet, the rate of adoption of hearing aid equipment continues to remain low, more so in the low and middle income countries, where the rate of adoption is close to a mere 3 percent compared to 20 percent in wealthier countries like the states, the major reason for this being the abhorrently high pricing of these equipments.

(Professor Bhamla at work)

Professor and his team incorporated innovative use of open source electronics to engineer a durable, self serviceable, yet affordable hearing aid that met most of the targets and standards set by the World Health Organization for mild-to-moderate agerelated hearing loss.

The group of scientists focused 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 of the device by narrowing the range of sound frequency amplification needed.

"The challenge we set for ourselves was to build a minimalist hearing aid, determine how good it would be and ask how useful it would be to the millions of people who could use it," said M. Saad Bhamla.

Modern hearing aids use digital signal processors to adjust sound. These components are generally too expensive and power hungry. The team therefore 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. An awe-inspiring example of how sometimes going back in time and embracing simplistic technology can prove to be immensely impactful.

When we put the math together, the fact that comes to light is that the cost of the electronic components of LoCHAid sums up to less than a dollar (around Rs.75), if purchased in bulk.Now, to keep the assembly and maintenance costs low, the strategy adopted was to keep the size of the device a little on the larger side. While this may not sound very appealing, it enabled the team to make use of low-tech assembly lines and even do-it-yourself production and repair. If this strategy is more widely adopted, there could be a massive breakthrough in the world of repair and maintenance.

The device has been designed to be powered by common AA or lithium ion batteries to keep the costs low and the battery life as long as three weeks compared to an average 4.5 day life of common zinc-air batteries. Another impressive feat.     The large size, although quite helpful in cutting costs, and increasing ease of repair, is one of the few drawbacks that the device has. Others being its inability to adjust frequency ranges (which is a result of the absence of signal processors) and its short lifetime of just about a year and a half.

The inexpensive hearing aid developed by Bhamla's team can obviously not do everything that the more expensive devices can do, an issue a member of the team compared to "purchasing a basic car versus a luxury car. If you ask most users, a basic car is all you need is to be able to get from Point A to Point B. But in the hearing aid world, not many companies make basic cars.” This gap, we can safely say, can effectively be bridged by the development of more such low cost, good quality hearing devices.

The researchers in Professor Bhamla’s team are now working on a smaller version of the device. Although, it would bump up the cost a bit, it would be a welcome move as it would still cost a tad less than the normal sophisticated hearing aid devices available in the market. Cheers to Professor and his team who have, in their words shown us that, “Low cost does not have to mean Low quality.”

Author : Sarthak Sharma

Disclaimer : The pictures in the article are for illustration purposes only. Neither the author nor IEEE Student Branch , BITS Hyderabad has any claim over them.

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