Once viewed with trepidation by hearing care professionals (HCPs) and clients, rechargeable hearing aids have become significantly more prevalent than devices that use disposable batteries.

To delve into why and what current models have to offer, The Hearing Review asked experts from several hearing aid manufacturers to share their thoughts on the most important trends in rechargeable hearing aids, how these trends can benefit HCPs and their clients, and what product innovations we can expect to see in the future.

Participating in this industry roundtable are Jennifer Groth, MA, senior principal audiologist in the hearing division of GN Group; Ina Seel, senior manager, Phonak reliability program; Brian Taylor, AuD, Signia’s senior director of audiology; Sara Burdak, AuD, Starkey’s chief audiology officer and executive vice president of product strategy; and Dana Helmink, AuD, senior director of audiological development at Widex USA.

Jennifer Groth (GN): The most obvious trend is simply that rechargeability is being introduced across the product range. Initially, we developed rechargeability for our receiver-in-the-ear (RIE) styles as this is the most popular. Now in ReSound Nexia, we offer rechargeable hearing aids across the portfolio. In order to do this, it is essential to continually work with leading battery suppliers that can make high performance cells in small form factors with high energy density.

Ina Seel (Phonak): One of the biggest trends in rechargeable hearing aids that is often taken for granted is improved safety. Trends like faster, longer lasting, and more efficient charging are obviously important. But at the end of the day, if the client considers the hearing aid unsafe, it won’t be used.

At Phonak, we believe safety must be something that’s never taken for granted. We’ve been successfully working with an encapsulated rechargeable battery for more than six years. Every Phonak rechargeable hearing aid has a fully encapsulated battery compartment that protects the wearer from any potential battery leakage while keeping out moisture and debris.

Brian Taylor (Signia): There are currently two major trends surrounding rechargeable hearing aids on the market right now. The first is that with each new product launch, battery lives (number of hours before charging is needed) continue to increase. The second is that the size of rechargeable batteries is decreasing, meaning rechargeability is available in increasingly smaller devices.

Recently, Signia launched Silk Charge&Go IX, the world’s first and only rechargeable, instant-fit completely-in-the-canal (CIC) hearing aid, a small and unobtrusive solution designed to deliver superior speech in noise performance. It also comes equipped with a built-in power bank to provide charging on the go and can be charged through USB 3.0 or with a wireless Qi charger.

Overall, easy charging solutions for the form factors that HCPs and their patients love most means longer wear times and maximum benefits.

Rechargeable batteries are a significant upgrade in powering hearing aids for patients. They are much easier to manage with user-friendly charging stations as compared to battery pills which require well-coordinated finger dexterity. Additionally, the conventional battery pill is inconvenient—patients have to take the time to buy them, store them, and dispose of them properly—whereas rechargeable batteries offer up the much simpler solution of placing them in a charging case, eliminating barriers to hearing health.

Sara Burdak (Starkey): Initially, the introduction of rechargeable hearing aids to the market was met with apprehension by both hearing professionals and patients alike. Their reservations stemmed from a fear that these devices might not provide enough battery life for all-day wear, potentially putting patients in situations where they couldn’t hear. Additionally, professionals expressed concerns with patients’ ability to remember to recharge their hearing aids, while some individuals simply liked the security provided by being able to replace a battery when needed.

Today, rechargeable hearing aids make up approximately 80% of the devices sold in the U.S. and we continue to see this percentage trending upward. This increase is due in part to the notable advancements made in increased battery life, consistent quality and reliability, as well as an improved battery life cycle. More and more patients ask for and expect their hearing aids to be rechargeable.

Starkey’s newly released Genesis AI and Starkey Signature Series product families have received countless praise for the industry leading rechargeable RIC battery performance of up to 51 hours of battery life. In addition, the world’s first truly custom rechargeable hearing aid, the Starkey Signature Series CIC R NW, has up to 38 hours of battery life. These long battery lives provide the peace of mind that patients need. Hearing aids can have outstanding reliability and years of performance no matter what the wearer’s degree of hearing loss, streaming preference, or lifestyle.

Dana Helmink (Widex): Battery technology improvements have received considerable focus in hearing aid design over recent years. Newer rechargeable battery technology provides an increasing ability to store energy, while decreasing the size of the battery. Recent hearing aids have well over a day of charge and offer portable chargers that also function as a power bank to allow even more flexibility and freedom to wearers.

The benefits of these technological advances can be seen with the new Widex SmartRIC featuring a groundbreaking hardware design where the unique choice of a pin-type battery delivers up to 37 hours of use (27 hours with a full day of streaming) in an aesthetic described as modern, sleek, and small.

The SmartRIC is paired with a compact portable charger that fits effortlessly in a bag or pocket and provides up to five recharges of the SmartRIC devices so that wearers can enjoy over a week of freedom before needing to plug back into an electrical source. Freedom from having to think about when or where to recharge one’s hearing aids can improve the experience for wearers.

For HCPs, there can be benefits in presenting hearing solutions that exceed the expectations of wearers who are transitioning from consumer audio products into their first set of hearing aids. Making power and streaming limitations a thing of the past can allow the wearer and HCP to focus on the more important aspects of hearing and communication.

Seel: When it comes to rechargeable technology, hearing care professionals and their patients value peace of mind, quality, and reliability. Hearing aid wearers should never be wondering whether their hearing aids are going to charge or not, and HCPs obviously don’t want to spend all their time on service or repairs.

Reliability is a top priority for Phonak. We develop our products using high quality, innovative materials for charging contacts and coatings. Then, we rigorously test our products in our own test lab, regularly pushing them beyond their limits to ensure reliability. As a result of our continuous improvements, we’re proud to have achieved more than a 30% reduction in service repairs for our rechargeable hearing aids.

Taylor: Between 2016 and 2020, there was a steep learning curve with rechargeable hearing aids—the quality was uneven and they were prone to failure. Over the past 3 to 4 years, the quality and reliability have become unmatched. Customer feedback over the past few years has been extremely positive.

Burdak: Rechargeable hearing aids, along with their chargers, are smaller and more discreet than ever. The ease of use and portability of the charger is essentially as important as the hearing aids themselves. Thoughtful design must be considered ensuring the hearing aids fit properly in the charger and provide clear indicators for charging status of the hearing aids.

Features like turbo charging (where a hearing aid can be charged in a matter of minutes to provide a quick extension to the battery life) also provide additional peace of mind. Starkey’s chargers come with on-board turbo charging, giving the wearer approximately 3 hours of hearing aid use with only 10 minutes of charging.

Helmink: The main benefit delivered by these trends in rechargeable technology is the convenience for both the HCP and the hearing aid wearer. Wearers gain an all-new level of freedom through convenience that matches their lifestyles. We hear from wearers reporting days full of streaming without worry about battery life and full weeks without having to plug in their charger. This frees them to stream an entire series in one day or pack for a weekend away without all the cords and plugs. Furthermore, overdelivering on battery life at day one means that the wearer will continue to experience worry-free battery life for years of use. One less thing to worry about for both the wearer and HCP.

HR: What advances can we expect to see in rechargeable hearing aids in the future?

Seel: Increasing the robustness of rechargeable hearing aids through waterproofing is a trend Phonak is proud to have started in 2021 with the introduction of Audéo Life, the world’s first mainstream rechargeable hearing aid. Audéo Life goes even further beyond an IP68-rating to provide HCPs with a sweat- and waterproof rechargeable hearing aid that maximizes peace of mind. Audéo Life features an innovative parylene coating that protects the hearing aid’s internal battery components from moisture damage, helping to reduce patient anxiety around water and other activities.

Taylor: In the coming years, it is expected that longer battery lives will be paired with smaller and more discreet styles of hearing aids.

New, more powerful charging cases have also become an asset to patients on the go. Styletto IX is available with a new Styletto IX charging case, which provides five full portable charges before needing to charge the case via Qi wireless technology or by plugging it into an outlet.

Burdak: The hearing aid industry has found a great source for meeting the requirements of the rechargeable design in lithium-ion (Li-ion) batteries. These batteries provide the best source of power in a small, reliable package. However, the future holds many possibilities; we could see new innovations arise that enable us to charge even more efficiently and conveniently.

We know office space can be challenging for professionals and they want a more universal charging approach that takes up less space. Starkey is always keeping a close eye on battery technology in adjacent spaces that would make a meaningful difference for the professional and patient if adopted in hearing technology. Starkey is committed to innovation in battery technology and creating the most seamless experience.

Helmink: Across many industries, a considerable amount of research investment is focused on rechargeable and renewable energy solutions. In the hearing industry we benefit from these ongoing innovations in other fields. 

We have seen in the past a capacity increase of about 20% every 3 years and we can expect that this development trend will continue. This allows us to look toward the future where we can continue to extend the processing power of the hearing aid. That is one of the reasons why Widex designs our own unique signal processing chips where we improve processing power for new audiological features to benefit the user, while keeping a small size and long enough battery life.

There are three major battery performance indicators driving innovation: energy density, charging cycles, and charging time. Currently, Li-ion technology offers the best balance of these parameters as applied in hearing technology, but ongoing developments in solid state and stacked batteries may provide interesting opportunities for very flexible form factors.

With Widex SmartRIC, our choice of pin-style battery is in part what allowed us to design a groundbreaking L-shaped design that puts the microphones at a more horizontal angle for better focus and speech understanding in noise. It is an interesting example of how battery innovation can contribute to audiological improvements and wearer benefits that go beyond hours of use.

HR: Do you anticipate ways that some rechargeable hearing aid limitations or drawbacks might be resolved? 

Groth: The Li-ion battery technologies that are used in hearing aids and many consumer products today involve some trade-offs that require careful management. While they have sufficient power density to run a hearing aid for at least a day, can be made in different sizes and shapes, and have a lifetime that aligns with the expected lifetime of a hearing aid, some disadvantages may potentially be solved with technologies on the horizon. 

One concern is safety; we have all heard stories of products with Li-ion batteries heating up or catching fire. A hearing aid is a medical device; we must therefore invest in making sure that overheating does not occur in charging or use of the hearing aids. 

Another drawback is handling and storage, as the products with this battery technology need to be stored at a specific state-of-charge and temperature, and not for an excessively long time in order to maintain performance. A better solution may prove to be solid state batteries which do not contain any flammable liquid and may also provide higher energy density, longer battery lifetime, and have fewer restrictions on handling and storage.

Seel: The Phonak team is hard at work exploring new avenues in custom hearing aids, aiming to deliver a personalized and exceptional hearing experience like never before. 

One challenge of existing rechargeable technology has been around ease of use of the charging system, particularly for people who have dexterity issues or vision impairment. Chargers that are too small or have complex controls can be challenging for some users. 

In other instances, poor connection between the charger and the hearing aids can lead to ineffective charging or intermittent charging. These are some of the things the Phonak engineering team is working to address via a proprietary magnetic retention system.

Taylor: In the future, I anticipate that it might be possible for the wearer to change out a battery pack. Currently, lithium-ion batteries last 4-5 years—roughly about the same lifespan as a hearing aid. However, if someone wanted to keep their existing hearing aids for another 2-3 years, they could prolong its life by changing out its battery pack, which is a spec not yet available for patients or HCPs at this point in time.

Burdak: Historically, the obstacles of rechargeable hearing aids have been related to power consumption, for both everyday hearing and streaming, in addition to size constraints. There has been a trade-off. Starkey has overcome these obstacles by being committed to delivering rechargeable products that meet or exceed the size expectations of the patient. Innovation in technology happens at a rapid pace and in many cases the size of components decreases with that innovation. 

We were the first to introduce a custom rechargeable solution. Now, Starkey’s Neuro Processor is a smaller package than our previous processors yet includes 6x more transistors and 4x the speed, providing significantly higher processing. This higher processing ability allows us to continue to add more advanced noise processing strategies and our innovative sensor technology to the hearing aid on top of streaming functionality without sacrificing wear time. 

The efficiency of Starkey’s Neuro Processor enables us to make tens of millions more adaptations in an hour compared to our previous processor while adding battery life.

Helmink: There are very few drawbacks with today’s rechargeable hearing aids. Continued focus on increasing battery capacity and speed of the charging cycles will continue to make this technology available to a wider range of wearers who may have specific use needs that differ from the typical wearer. 

Photo: Dreamstime

Original citation for this article: Groth J, Seel I, Taylor B, Burdak S, Helmink D. Roundtable: Why Rechargeable Hearing Aids Are Trending. Hearing Review. 2024;31(5):16-19.