Medical Devices Today
Published May 1, 2015 – 3:23 pm
By Sam Brusco, Associate Editor, @SamISureAm
Listen Up! This New Hearing Aid Design Is an Earful
It is my pleasure to introduce Dr. Sreekant Cherukuri, M.D. He is a board certified otolaryngologist (ear, nose, and throat surgeon) and for over ten years has been treating hearing loss patients and prescribing them hearing aids. Dr. Cherukuri noticed that many of the patients for whom he was recommending hearing aids went untreated. This was a direct result of cost, as most hearing aids average around $1,600 – and that’s just for one ear. Many patients require a hearing aid for both ears, doubling the already exorbitant cost. Dr. Cherukuri looked into the reasoning behind these inflated costs, and noticed many inefficiencies in hearing aid design and distribution. With the help of his brother, an engineer and MBA, he founded MDHearingAid to manufacture medical grade, one-size-fits-most hearing aids at a far lower cost. Dr. Cherukuri took the time to speak with me about his revolutionary line of hearing aids, and offer his insight into best practices for hearing aid design.
Q: What are the benefits of a design for the “bowl” of your ear over those customized for the ear canal?
Dr. Cherukuri: Custom ear canal hearing aids, known as In-the-Canal (ITC) aids are subject to the heat, humidity, and cerumen (earwax) of the ear canal, and thus have the potential for a high failure rate. Also, many people have narrow ear canals that make for an uncomfortable or impossible fit. The advantage of our MDHearingAid FIT is that it sits in the ‘bowl’ of one’s ear which is a more consistent anatomical shape from person to person and avoids the harsh environment of the ear canal.
Q: How were you able to cut the cost so drastically?
Dr. Cherukuri: Traditional hearing aids are distributed in a one-on-one fashion in a brick-and-mortar setting. There are many layers of middlemen and markup so the final product is quite expensive. When analyzing a $5,000 hearing aid, we realized that there are typically less than $300 in component costs. MDHearingAids are manufactured with the highest quality of medical-grade hearing aid components, designed to fit the most common types of hearing losses, and empower the user to make adjustments to the sound output. This is a scalable e-commerce model, so many of the costs of the traditional setting are eliminated
Q: What were the MDHearingAid FIT’s design challenges?
Dr. Cherukuri: The main challenges were that there were no traditional hearing aids utilizing this part of the external ear to house a hearing aid. However, we realized that while there was great variation in the size and shape of people’s ear canals – the external ears in general have a more consistent shape. One question we encountered early on is how we should go about measuring gain (loudness).
The FIT is quite unique in that it is a non-occluding ITE, and because the entry point to the ear canal of the MDHearingAid FIT is different from person to person – the standard ways in which traditionally measure gain and sound quality don’t exactly apply. Because of the variability of wearers, we had to use a best in class feedback reduction algorithm.
Q: How did you come to the conclusion that full hearing aid customization is unnecessary?
Dr. Cherukuri: There have been medical studies that confirmed that non-custom hearing aids provided similar user satisfaction scores and perceived benefit as custom programmed hearing aids. Also, I realized that even with full customization, there was a significant patient dissatisfaction, in part since the end user has very little control over the sound output. This is in part due to the fact that hearing aids are programmed based on hearing test results from a sound-proof booth, but people don’t live in a sound-proof booth.
My senior audiologist and I have reviewed thousands of audiograms (hearing tests) and were able to categorize the vast majority in to 2-3 categories. Putting these factors together, we designed MDHearingAids to provide amplification of the critical frequencies of the human voice in algorithms that would meet the requirements of most people with hearing loss, AND we empowered the user to make sound adjustments according to their environment and specific needs.
Q: What benefits or issues arise from the MDHearingAid FIT output’s distance from the microphone?
Dr. Cherukuri: Actually, there is a greater distance between the MDHearingAid FIT‘s microphone and output compared to some ITC models. This allows for less acoustic feedback. Compared to a behind-the-ear hearing aid where the microphone is behind the ear, the MDHearingAid FIT design more closely mimics the natural design and function of the ear. This also means that the FIT can take advantage of the natural shape of the ear which is designed to help us hear better in background noise and locate sound.
One of the biggest benefits to the FIT is that it takes advantage of the pinna effect. The pinna (visible part of the ear) is funnel-shaped for a reason (to help route sound into the ear canal) and the FIT uses this to its advantage.
Q: What is the future for your company’s hearing aid design?
Dr. Cherukuri: We are continually surveying our customers to better understand their needs. While I cannot reveal what is in our product pipeline, it is safe to say that MDHearingAid will be introducing unique products to the direct-to-consumer markets with technological features previously only found on the high-priced custom hearing aids.
Q: Is there anything else you’d like to say regarding hearing aid design?
Dr. Cherukuri: I think a critical part of our success is that we designed our hearing aids based on my experience with thousands of patients in the physician office setting. I believe MDHearingAid has the greatest understanding of what the hearing loss customer’s requirements are.