From Quiet to Connected With Cochlear Implants

The use of cochlear implants to treat children and adults with severe sensorineural hearing loss has made “incredible progress” over recent years, according to Christopher Bohr, MD, PhD, director of the Otorhinolaryngology (ENT) Clinic at the University Hospital of Regensburg (UKR) in Regensburg, Germany. He told delegates at the Regensburg Hearing Day 2024 that cochlear implants offer affected patients the opportunity to communicate better and engage in social life — it’s all about quality of life and achieving the “best possible outcome” for patients.

However, surgical timing is crucial, and lifelong follow-up is necessary. Ongoing care is a highly complex process that is becoming increasingly personalized and requires high-quality standards and close collaboration among ENT specialists, radiologists, audiologists, hearing aid acousticians, speech therapists, and other disciplines. “It takes a large network,” said Peter Kummer, MD, specialist in Phoniatrics & Pediatric Audiology at UKR.

“When hearing disorders are not adequately recognized and treated, they impact the patient’s entire lifespan,” Veronika Neumeyer, PhD, of the East Bavaria Cochlear Implant Center, UKR, told the audience. Kummer agreed, saying that timing is critical for children, as the auditory pathways develop best when functional hearing supports language acquisition.

“The early years are crucial,” he said, and cochlear devices are most beneficial when implanted within the first 6-12 months of life. This makes early detection of hearing impairment essential. “We don’t have much time.”

Seizing Developmental Windows

“Only half of childhood hearing impairments are congenital,” Kummer explained. Many of these cases are due to c ongenital cytomegalovirus infection, which is thought to be the main cause of nongenetic sensorineural hearing loss. Another common cause is meningitis-related hearing loss, when timing is even more pressing, he said, as fibrosis or ossification of the cochlea could later prevent electrode insertion. Hence, tools such as newborn screenings, hearing tests for at-risk children, and language development evaluations during pediatric check-ups are key.

When Hearing Aids Insufficient

Approximately 4000 cochlear implants are fitted annually in Germany, according to Anke Lesinski-Schiedat, MD, PhD, Department of Otorhinolaryngology at the Medical University of Hannover, Hannover, Germany.

According to the local consensus-based guidelines, cochlear implants are an option for treatment if they are expected to offer better hearing and speech comprehension than hearing aids, bone conduction devices, or implantable hearing systems. Implants still have excellent success for pediatric patients who were not treated and developed hearing impairment before they began to speak, although results are variable and not as good as for children implanted earlier. Implants are even recommended for untreated prelingually deaf adults, for whom they may provide acoustic orientation.

For the initial approach to treatment of hearing impairment, sound conduction should be optimized, possibly with reconstructive surgery on the middle ear. However, when sensory hair cells in the cochlea can no longer send electrical impulses to the auditory nerve, cochlear implants become the only remaining option to stimulate hearing.

Signs that a hearing aid is no longer sufficient include increasing difficulty understanding speech despite optimal adjustments. “When phone calls are no longer possible with a hearing aid, that’s a tipping point,” said Steven Marcrum, PhD, AuD, an audiologist at UKR. Accurate tuning involves objective measures like real-ear testing and determining the speech intelligibility index to make “what is audible truly understandable.”

The 60/60 Rule Decider

Lesinski-Schiedat uses a unique approach to test speech comprehension using five-word nonsense sentences to prevent patients from guessing the content. Marcrum referenced the “60/60 rule”: candidates with a 60 dB hearing loss — or 70 dB in children — in pure-tone audiometry over frequencies of 500 Hz, 1 kHz, 2 kHz, and 4 kHz, or those who understand ≤ 60% of single syllables in speech tests at a 65 dB level, may benefit from a cochlear implant.

Further evaluation, including personal hearing history, age, language development, and social factors, helps clinicians to assess the potential benefits of an implant. Individual goals, such as being able to listen to concerts or attend lectures, are also considered.

Genetic sequencing may also be worthwhile. “A significant number of hearing-impaired people likely have a genetic predisposition,” noted Lesinski-Schiedat.

“Bone and soft tissue imaging, using flat-detector CT and MRI, to evaluate for tumors or malformations are essential before any surgery,” she added.

Electrode Position Matters

Implant surgery may also be tailored to individual cochlear anatomy and individual goals. The electrode length can now be calculated using specialized software, and placing the electrode deeper into the tissue helps reach regions responsible for low-frequency sound perception, advantageous for music lovers who want to hear bass sounds.

Conversely, for age-related hearing loss, where high-frequency hearing often deteriorates first, the hair cells in the cochlear apex may remain intact. A shorter electrode may be preferable in these cases to avoid damaging these cells.

A minimally invasive approach, with minimal scarring and trauma to the cochlea, is optimal, said Lesinski-Schiedat. For residual low-frequency hearing, a hybrid solution combining a hearing aid with a cochlear implant can be effective, utilizing the hearing aid to offer sound quality with the implant component to enhance clarity.

Experimental options, like biohybrid electrodes with stem cells, may also offer hope for repairing damaged tissue and enhancing hair cell numbers.

Hybrid Care

Binaural hearing is generally preferred, so both ears are implanted when indicated. A potential benefit of cochlear implants is the suppression of tinnitus, although this is not guaranteed.

Despite the decline in benefit with prolonged deafness, age alone is not a barrier to a cochlear implant, said Lena Rossmann, specialist in otorhinolaryngology at UKR, who noted the oldest implant recipient was 103 years old. “If patients are cognitively and physically capable of undergoing the surgery and rehabilitation, then please refer them,” she said.

Adapting to an Implant

Adjusting to hearing through a cochlear implant requires training, and rehabilitation capability and motivation — including parental involvement for children — are essential, Neumeyer explained. Hearing through an implant “sounds different from normal hearing,” highlighting the need for ongoing individual adjustments, rehabilitation, and lifelong follow-up. “It’s a continuous dialogue between our team and the patient, adapting to what matters most to the patient.”

This story was translated from Medscape’s German edition using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.