A cochlear implant is an electronic device that can restore sound perception in people with certain types of severe hearing loss by picking up sound from the environment, converting that sound into electrical impulses, and transmitting those impulses directly to the auditory nerve. In this video, I discuss the components of a cochlear implant and how they work together to create sound perception.
TRANSCRIPT:
A cochlear implant is an electronic device that can restore sound perception in people with certain types of severe hearing loss by picking up sound from the environment, converting that sound into electrical impulses, and transmitting those impulses directly to the auditory nerve. Cochlear implants provide an option for hearing restoration in patients who have more extensive hearing loss, and for whom a device that simply amplifies sound (such as a hearing aid) may not be as effective. A cochlear implant is an example of a neural prosthesis, as it replaces the disrupted functionality of the cochlea with an electronic device to restore functional hearing.
Cochlear implants consist of both external and internal components. The external component typically sits behind the ear and picks up sound through a microphone; when sound is detected, a sound processor converts the auditory information into a radio frequency signal. The signal is transmitted to a receiver implanted under the skin behind the ear. The receiver decodes the signal, then converts it into electrical currents, which are sent along wires that have been surgically inserted into the cochlea. The wires stimulate the auditory nerve (a job typically reserved for the damaged cochlear cells), and stimulation of the nerve causes auditory information to be sent to the brain to create sound perception.
A cochlear implant does require surgery, but major complications are uncommon. Studies have generally found cochlear implants to be beneficial, but the extent of the benefit does vary depending on the patient, with children who get cochlear implants earlier and adults who get them soon after hearing loss typically experiencing the greatest benefits.
REFERENCES:
Naples JG, Ruckenstein MJ. Cochlear Implant. Otolaryngol Clin North Am. 2020 Feb;53(1):87-102. doi: 10.1016/j.otc.2019.09.004. Epub 2019 Oct 31. PMID: 31677740.
Zeng FG, Rebscher S, Harrison W, Sun X, Feng H. Cochlear implants: system design, integration, and evaluation. IEEE Rev Biomed Eng. 2008;1:115-42. doi: 10.1109/RBME.2008.2008250. Epub 2008 Nov 5. PMID: 19946565; PMCID: PMC2782849.
Image of cochlear implant on head at :05 drawn by Michelle Dingman.
