Most of the devices now have Bluetooth wireless connectivity that allows the implant to be connected to a cellphone or other devices. External microphones, or FM systems, that relay the information from the speaker directly to the implant are also available—“this improves the signal-to-noise ratio and substantially improves performance in noise,” Dr. Buchman said.
Explore this issue:November 2017
Hybrid and EAS Implants
One of the expanding goals of cochlear implants is to maintain or preserve hearing. Right now, many people who have age-related hearing loss—hearing loss in the high-frequency basal turn, but preserved low-frequency hearing in the apical end of the cochlea—are not candidates for cochlear implants. For these patients, the implantation of a hybrid device may be a great option.
There are currently two such devices: Cochlear Hybrid Hearing by Cochlear Corporation and EAS (Electric and Acoustic Stimulation) by MED-EL. Both devices use shorter electrodes and are therefore less likely to traumatize the apical end of the cochlea, Dr. Lalwani explained. The devices are only placed where there is hearing loss isolated at the basal turn of the cochlea. “The goal is to have the electrode be short enough not to traumatize the inner ear, preserve the low-frequency hearing, and only stimulate the hearing in the high-frequency nerve fibers,” he added.
“By preserving the low-frequency hearing, patients are able to utilize their residual acoustic hearing in the implanted ear. This approach opens the doors for a broader range of hearing losses to benefit from this technology [combined electrical and acoustical hearing],” Dr. Blackburn added.
“Emerging indications are finding great utility in select populations,” Dr. Buchman said, “including patients with single-sided deafness and/or those with hearing loss together with incapacitating tinnitus. Amazingly, the cochlear implant can drastically reduce tinnitus in some patients. For people with single-sided hearing loss, they have significant improvement in sound localization and hearing in noisy environments. And for the EAS or hybrid implants, those patients can show significant improvement in performance that more closely approaches normal hearing than anything that we have had before.”
Social Cost of Hearing Loss
Ten percent of the U.S. population has significant hearing loss, Dr. Buchman noted. A number of studies have looked at the psychosocial impact of hearing loss. Perhaps most upsetting to patients and family members is the social withdrawal. “The number one comment I hear from patients is that they feel alone and isolated because of the hearing loss—it impacts their ability to communicate and affects their relationships with family and friends,” Dr. Blackburn said.