A cochlear implant (CI) is an electronic device that provides a sense of sound to individuals with severe to profound hearing loss by bypassing damaged parts of the inner ear. Unlike a hearing aid, which only amplifies sound, the CI system converts sound into electrical signals that directly stimulate the auditory nerve. This complex process requires a constant and reliable power source. The immediate answer to whether a cochlear implant needs batteries is yes, but only for the external component of the device.
Powering the Device: The External Processor’s Role
The battery powers the external sound processor, which is the visible component worn on the head or behind the ear. This external unit performs several energy-intensive tasks continuously to enable hearing. It contains a microphone that captures sound waves and converts them into digital data.
The digital signal processing (DSP) unit then analyzes and refines this sound information, separating different frequencies and adjusting volume levels. Finally, a transmitter coil wirelessly sends this coded digital signal and the necessary power across the skin via a radio frequency (RF) link to the internal, surgically implanted component. The internal implant receives all its power and data through this inductive link from the external processor.
Comparison of Power Options
Cochlear implant users have two primary power options for their external processors: rechargeable batteries and disposable batteries.
Rechargeable Batteries
Rechargeable batteries, typically lithium-ion (Li-ion) cells, offer convenience and are environmentally friendly. These batteries provide power for a full day, with run times ranging from 8 to 18 hours per charge, depending on the processor settings. They require nightly charging, similar to a smartphone. The battery unit generally has a lifespan of around 365 to 500 charge cycles before its performance degrades.
Disposable Batteries
Disposable batteries are zinc-air chemical cells (size 675 or PR44) activated upon exposure to air when a protective tab is removed. These batteries offer the flexibility of quick replacement and can last significantly longer than a single charge of a rechargeable unit. Depending on the processor model, disposable batteries can last anywhere from one to five days, or approximately 30 to 80 hours of use. Users must consider the recurring cost of purchasing new disposable batteries and the resulting waste.
Extending and Maintaining CI Battery Life
Users can adopt several practices to ensure their batteries perform reliably. For rechargeable Li-ion batteries, it is better to recharge them every night rather than letting them fully drain. Lithium-ion chemistry is sensitive to being completely discharged, which can shorten the overall lifespan.
For disposable zinc-air batteries, wait approximately two minutes after removing the protective tab before inserting them into the processor. This waiting period allows the zinc-air chemistry to fully activate and reach its optimal power level. Both rechargeable and disposable batteries should be stored in a cool, dry place away from extreme heat or direct sunlight, as temperature fluctuations negatively affect performance.
Device usage habits also influence battery consumption. High volume settings or prolonged periods of wireless audio streaming draw more power. When the processor is not in use, opening the battery compartment or turning the device off completely prevents unnecessary power drainage. Regular cleaning of the battery contacts ensures a consistent electrical connection necessary for efficient power transfer.