FDA OKs Cochlear Device for Sensorineural Hearing Loss

Megan Brooks


March 21, 2014

The US and Drug Administration (FDA) has approved the first implantable hearing device for people aged 18 years and older with severe or profound sensorineural hearing loss of high-frequency sounds in both ears but who can still hear low-frequency sounds with or without a hearing aid.

The Nucleus Hybrid L24 Cochlear Implant System, manufactured by Cochlear Ltd of New South Wales, Australia, combines the functions of a cochlear implant and a hearing aid and may help patients with sensorineural hearing loss who do not benefit from conventional hearing aids, the FDA said in a statement March 20.

"This device has complimentary technologies in 1 package in 1 ear," Daniel Lee, MD, director, Pediatric Otology and Neurotology, Massachusetts Eye and Ear Infirmary, Boston, told Medscape Medical News.

This device represents a "broader trend in what we are doing with Cochlear implants, which is trying to preserve hearing, using acoustic and electric stimulation," Larry Lustig, MD, chief of neurotology and director of the Cochlear Implant Program at the University of California, San Francisco, who participated in the clinical trials of the device, told Medscape Medical News.

Limited Treatment Options

Sensorineural hearing loss, the most common form, stems from damage to the inner ear (cochlea) caused by aging, heredity, exposure to loud noise, drugs that are toxic to the inner ear (such as antibiotics), and certain illnesses.

People with sensorineural hearing loss in the high frequencies have trouble hearing voices clearly, understanding speech, and in some cases, hearing high-pitched emergency vehicle sirens or common safety alarms, such as smoke detectors, the FDA notes.

"Hearing loss greatly impacts the education, employment, and well-being of many Americans," Christy Foreman, director of the Office of Device Evaluation at the FDA's Center for Devices and Radiological Health, said in the FDA statement. "This device may provide improved speech recognition for people with this kind of hearing loss, who have limited treatment options."

The Nucleus Hybrid Cochlear Implant System features an external microphone and speech processor that picks up sounds from the environment and converts them into electrical impulses, which are transmitted to the cochlea through implanted electrodes, "creating a sense of sound that the user learns to associate with the mid- and high-frequency sounds they remember," the FDA notes. The hearing aid portion of the device is inserted into the outer ear canal similar to a conventional hearing aid and can amplify sounds in the low-frequency range.

In approving the device, the FDA considered results of a clinical trial of 50 individuals with severe to profound high-frequency hearing loss who could still hear low-frequency sounds.

Most of the patients reported statistically significant improvement in their ability to recognize words and sentences 6 months after the device was activated compared with their preimplant performance using a conventional hearing aid, the FDA said.

In clinical testing, 68% of patients experienced 1 or more "anticipated" adverse events, such as low-frequency hearing loss, tinnitus, electrode malfunction, and dizziness, the agency notes.

Discuss Risks and Benefits

In addition, 22 people developed profound or total low-frequency hearing loss in the implanted ear, and 6 had additional surgery to replace the Nucleus Hybrid L24 Cochlear Implant System with a standard cochlear implant.

The FDA said that although the risk for low-frequency hearing loss is "of concern," they have concluded that the overall benefits of the device outweigh this risk for those who do not benefit from traditional hearing aids.

The FDA encourages physicians to "carefully discuss" all benefits and risks of the device with prospective patients.

"There is a lot of information that is extremely important for oral communication that is encoded in the low-frequency sound that the Hybrid device can tap into if one has successfully preserved that hearing during the cochlear implant portion of the surgery," Dr. Lee told Medscape Medical News.

"But no matter how minimally [invasively] you place the electrodes during surgery, there is still going to be a risk of losing hearing," he said. "You are putting an electrode through a hole in the inner ear. The FDA has reasonable concerns because they know that the outcomes are variable and that we can't always save hearing in every case. Despite our best attempts to be extremely gentle, sometimes hearing is lost."

"It's not foolproof," Dr. Lustig added. "There is a risk of hearing loss in those low tones. But the data are very clear: Even in those patients who lost hearing, they still did better with the Hybrid [device] than they did with their prior hearing aid."

Dr. Lustig is on the medical advisory board of Med-El Corp and Advanced Bionics Corp. Dr. Lee is a research grant recipient from MED-EL Corporation, is on the surgical advisory board for Cochlear Corp and MED-EL, and is on the medical advisory board for Agilis Health Inc and Otology Solutions, LLC.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: