Your phone’s rechargeable, as are your camera and toothbrush. So why shouldn’t your hearing aids be rechargeable, too? In fact, there are now different kinds of rechargeable hearing aids on the market. Read on to find on how to choose the right one for you.
The rechargeable battery
The first thing to consider when evaluating different rechargeable solutions is the type of battery. Not all rechargeable batteries are created equal. Here are three major kinds of rechargeable batteries:
Nickel metal hydride (NiMH) cells are a long-proven type of rechargeable battery because both NiMH and zinc-air types can be used (and interchanged whenever desired) for the same hearing aid. One drawback of the NiMH battery is that its capacity is still limited. While sufficient for hearing aids fit to milder losses, it may not be suitable for those who have more severe hearing loss.
Silver-zinc (AgZn) batteries have a higher energy density than zinc-air batteries and NiMH batteries, while maintaining good discharge rate capability. This mean AgZn batteries can last longer on a single charge. They are non-flammable and fully recyclable. However, AgZn batteries are not interchangeable with disposable zinc-air batteries, and can only be used with dedicated hearing aids with a down-converter. Silver-zinc cells may need to be replaced about once a year.
Lithium-ion (Li-Ion) defines a completely new family of rechargeable cells. These batteries come with many advantages, which explains their widespread use in all kinds of consumer electronics. They can run an electronic device for a long time even with high energy demands. Li-Ion technology allows for a fast charging mode. They don’t show memory effects, and can be sealed in the hearing aid for their entire lifetime ― a relief for individuals with dexterity or vision limitations. Remaining sealed inside the hearing aid also means that the battery is less likely to be accidentally swallowed by small children or pets.
One drawback for Li-Ion batteries is that under stress conditions like extreme pressure or heat, they can overheat. Therefore, only long-proven battery manufacturers that routinely perform internal stress tests can be regarded as suitable for the production of the small lithium-ion cells required for hearing aids.
Currently there are two methods of charging. Most conventional battery chargers are still based on galvanic charging ― electronic contacts on a cradle physically touch their counterparts on the electronic device so that the device can be charged. This means devices always need to be placed at an exact position in the cradle so that the electric contacts are well-aligned, which can be a burden for those with vision or dexterity limitations.
The alternative is wireless inductive charging that eliminates cables, connectors, and electrodes on the hearing aids. Inductive charging works via electro-magnetic induction and eliminates the need for contacts, which allowed Signia to design a completely sealed battery module. This offers many advantages, including:
- Increased ease of use because exact placement of the device in the charger’s cradle is not required
- No hassling with opening and closing a battery door
- No electronic contacts that can collect dirt and debris
- Improved water, sweat, and dust-resistance
Which is the right rechargeable hearing aid for you?
Rechargeable batteries can save you money and hassles, and also help to save the environment by reducing the toxic waste caused by disposable batteries. In choosing the right rechargeable solution, it is important to ask your hearing care professional about the type of rechargeable battery and charging method to best suit your needs and priorities.
Finally, while rechargeable hearing aids are worth consideration, your priority should always be finding the hearing aids that helps you to hear as well as you can in as many situations as possible, and one that fits your lifestyle.