By Michelle Soares Mendes, Senior Audiologist
Anyone who owns a mobile phone would be forgiven for thinking that everyone uses rechargeable technology. But that has not been the case in hearing aid arena until just now. The good news is the new technology originally developed by NASA and the Department of defense in the USA has developed a solution that finally makes rechargeable hearing aid batteries more practical, cost-effective and a much smaller available solution.
So what’s the problem?
Modern high-performance hearing aids pack a lot of performance into a very small package. Powerful digital signal processing chips provide sophisticated feedback cancelling, noise reduction and multiple programs for a variety of listening environments. Self adjusting directional microphones seek out the sources of voices you want to hear. And wireless transceivers stream audio from mobile phones and other audio sources. All this performance requires a lot of power. A battery that would adequately drive such powerful hearing aids would be potentially quite large and not charge for full day of use. These challenges have now been overcome and a range of options are available with all the hearing aid manufacturers. Rechargeable batteries are now long-lasting, safe, environmentally friendly and easy to use.
Currently there are three options when choosing the batteries for your hearing aids.
1.Hybrid Z power rechargeable batteries.
In collaboration with Z-Power, many hearing aid manufactures including Unitron, Oticon, Starkey, Widex, and GN resound now use this technology for their hearing aid batteries.
Early rechargeable hearing aid batteries were made from nickel-metal hydride (NiMH) technology. When the Department of Defence and NASA discovered that NiMH technology wasn’t useful for certain military and aerospace applications, they searched for another solution. They came up with silver-zinc. In fact, it was newly developed silver-zinc batteries, which held a charge longer and met size constraints more easily, that provided backup power necessary for the damaged Apollo 13 to make it I, back to Earth safely after it circled the moon.
This technology has been developed for hearing aids and has the beauty of being able to interchange between disposable and rechargeable silver zinc battery. Meaning that if you forget your charger or don’t ‘have access to power, the disposable batteries can be used as a back up for emergencies.
The Silver-zinc rechargeable battery is non-flammable, non-toxic and 100% recyclable. Also the higher energy density means a silver zinc battery can come in a smaller package compared to equivalent lithium-ion rechargeable batteries. Charging time to reach full capacity is roughly 4 hours and the battery life cycle is one year.
2. lithium ion Rechargeable batteries
The Phonak and Siemens hearing aids are based on built in lithium-ion batteries.
The lightest of all rechargeable batteries, Lithium Ion is used in everyday consumer electronics such as smart phones, cameras, power tools and cars. Li-ion batteries pack a punch offering the fastest charging time and the longest lasting battery on the market today. It provides enough power for 24 hours of wearing time before recharging is required. The battery can be completely depleted and recharged in three hours. The battery will last for 4 years before needing replacement.
The capacity of a Li-ion battery does not decrease with repeated short charging sessions, nor is the hearing performance affected over time. Li-ion devices can be charged often for short or long periods of time without the risk of harming the battery capacity or life cycle.
3. Conventional disposable batteries
Conventional batteries are usually Zinc-air. They need to be replaced every 1-2 weeks and are disposed of but can be recycled. Zinc air batteries are popular as they can be readily purchased throughout the world. In Australia pensioners also obtain a significant subsidy for their batteries.
So what is the best option?
Rechargeable is definitely our recommendation. The benefits are too great to ignore. Recharge kits can also be retrofitted to quite a number of existing hearing aid brands so come in to Dunsborough & Margaret River Hearing to find out more.
Contact the clinic on 9794 6189