Cochlear implants explained: Benefits, risks, and real-life impact
October 13, 2025
Many Americans don’t receive hearing tests or treatment, even though hearing loss can be connected to other serious health issues and/or reduce quality of life. It’s estimated that over 50 million Americans have some degree of hearing loss, and it’s twice as prevalent as diabetes or cancer. For some of these people, hearing aids are not a powerful enough tool. Instead, they may consider cochlear implants.
“These implants restore sound, but they also restore connection, confidence and quality of life. That’s my entire goal as an audiologist,” says Heidi Schmeltzer, audiologist at Saint Joseph Health System.
What is a cochlear implant?
A cochlear implant is a surgically implanted device that transmits sounds directly to the cochlea, the cavity of the inner ear containing the organs Corti and basilar membrane which produce nerve impulses in response to sound vibrations. This direct stimulation represents a key difference between a cochlear implant and hearing aids.
Hearing aids simply amplify sounds, like raising the volume on a radio, to help the patient hear better. Cochlear implants provide electrical stimulation, sending signals directly to your hearing nerve and on to the brain.
How does a cochlear implant work?
The implant consists of two primary components; the internal and external portions. On the outside, there is a microphone and sound processor. Inside the ear is a receiver and electrode array. The implant improves hearing through the following process:
- The microphone captures sound which the sound processor converts into a digital signal which it then sends to the transmitter.
- The transmitter converts the digital signal into electrical impulses.
- The electrical impulses are sent to the electrode array which then distributes the impulses and sends them to different regions of the auditory nerve.
Who is a candidate for cochlear implants?
Cochlear implants are not the first option for those suffering from hearing loss. Instead, hearing aids are recommended first. However, if patients find that their hearing aids are no longer effective, cochlear implants may be considered.
“When people are noticing that with appropriately-fitted hearing aids they're still wanting the TV volume increased, they're still struggling in conversations, they're withdrawing from social situations, that's when we visit the option of cochlear implants,” says Dr. Schmeltzer.
If a patient believes that hearing aids or other methods are not improving their hearing loss, a doctor of audiology will perform a hearing test to determine cochlear implant candidacy. The type of test and required scores are different depending on if the potential recipient is a child or adult. For adults 18 years or older, cochlear implant candidacy requires:
Moderate to profound sensorineural hearing loss in both ears
- Limited benefit from amplification defined by preoperative test scores of less than 50% sentence recognition in the ear to be implanted and less than 60% in the opposite ear or binaurally.
The surgical process of cochlear implants
Compared to many other surgeries, cochlear implant surgery is fairly straightforward. It’s an outpatient procedure, meaning the patient returns home the same day. The surgery is performed under general anesthesia and generally takes 1 to 4 hours.
First, the ear, nose, and throat surgeon makes a cut behind the ear to access the mastoid bone, the bumpy area behind your ear. They then make an opening into the cochlea to insert the implant electrodes, then place a receiver under the skin behind the ear. The incision is then closed.
In general, patients report minimal side effects, mostly related to swelling, temporary balance issues and ringing in the ears, all of which are usually temporary. The external portion of the implant will not be fitted and activated until 3 to 4 weeks after the surgery. This allows time for the incision to heal and swelling to reduce.
Rehabilitation and training
Following cochlear implant surgery, patients don't suddenly experience improvement to their hearing. They must now start a process of rehabilitation and adaptation. Because cochlear implants deliver sound via electrical signals rather than the ear’s natural acoustic pathway, the brain must learn to interpret these signals in a new way. Initially, many patients describe the sound as robotic or digital, but with consistent use and training, the brain gradually adjusts, improving speech recognition and overall sound quality.
“Most patients begin to notice improvement within the first 6 to 12 months after activation, and we typically expect at least a 20% increase in speech understanding scores during that time,” says Dr. Schmeltzer.
This is measured by comparing pre- and post-implant speech scores in both quiet and noisy environments. To support this progress, patients are encouraged to wear their sound processor consistently and engage in auditory training exercises.
However, patients won’t just be seeing their audiologist to help them train. An important part of the process is what they do at home. One of the most vital steps per research is daily wear time of at least 8 to 10 hours. Other rehabilitation tools include:
- Mobile apps that help users distinguish between sounds and syllables.
- Online modules for self-guided practice.
- PC-based programs that track progress over time.
- Speech therapy, especially for children, to support articulation and language development.
Patients typically return to their audiologist for four follow-up visits in the first year, during which the device is reprogrammed to optimize sound delivery based on individual progress and feedback.
“We test various things to make sure that patients are improving. Can they identify if a noise is present or not present? Can they identify one-syllable words versus two-syllable words? We train for those things and many others, building over time,” says Dr. Schmeltzer.
Lifestyle changes
In terms of lifestyle, modern cochlear implants are designed to be durable and moisture-resistant, allowing users to comfortably navigate daily activities like walking in the rain or playing at splash pads. While the devices are not rated for prolonged underwater use, accessories are available to make them fully waterproof for swimming. For those involved in contact sports, specialized helmet inserts can protect the implant site, enabling safe participation.
