Cochlear implant

Cochlear implant
Diagram of a cochlear implant

A cochlear implant (CI) is a surgically implanted neuroprosthesis that provides a person who has moderate-to-profound sensorineural hearing loss with sound perception. With the help of therapy, cochlear implants may allow for improved speech understanding in both quiet and noisy environments.[1][2] A CI bypasses acoustic hearing by direct electrical stimulation of the auditory nerve.[2] Through everyday listening and auditory training, cochlear implants allow both children and adults to learn to interpret those signals as speech and sound.[3][4][5]

The implant has two main components. The outside component is generally worn behind the ear, but could also be attached to clothing, for example, in young children. This component, the sound processor, contains microphones, electronics that include digital signal processor (DSP) chips, battery, and a coil that transmits a signal to the implant across the skin. The inside component, the actual implant, has a coil to receive signals, electronics, and an array of electrodes which is placed into the cochlea, which stimulate the cochlear nerve.[6]

The surgical procedure is performed under general anesthesia. Surgical risks are minimal and most individuals will undergo outpatient surgery and go home the same day. However, some individuals will experience dizziness, and on rare occasions, tinnitus or facial nerve bruising.

From the early days of implants in the 1970s and the 1980s, speech perception via an implant has steadily increased. More than 200,000 people in the United States had received a CI through 2019. Many users of modern implants gain reasonable to good hearing and speech perception skills post-implantation, especially when combined with lipreading.[7][8] One of the challenges that remain with these implants is that hearing and speech understanding skills after implantation show a wide range of variation across individual implant users. Factors such as age of implantation, parental involvement and education level, duration and cause of hearing loss, how the implant is situated in the cochlea, the overall health of the cochlear nerve, and individual capabilities of re-learning are considered to contribute to this variation.[9][10][11][12]

  1. ^ "NCD - Cochlear Implantation (50.3)". Centers for Medicare & Medicaid Services. Retrieved 2021-11-22.
  2. ^ a b "Cochlear Implants". NIDCD. 24 March 2021. Retrieved 2021-11-22.
  3. ^ Rayes H, Al-Malky G, Vickers D (May 2019). "Systematic Review of Auditory Training in Pediatric Cochlear Implant Recipients". Journal of Speech, Language, and Hearing Research. 62 (5): 1574–1593. doi:10.1044/2019_JSLHR-H-18-0252. PMID 31039327. S2CID 141503740.
  4. ^ Henshaw H, Ferguson MA (2013-05-10). "Efficacy of individual computer-based auditory training for people with hearing loss: a systematic review of the evidence". PLOS ONE. 8 (5): e62836. Bibcode:2013PLoSO...862836H. doi:10.1371/journal.pone.0062836. PMC 3651281. PMID 23675431.
  5. ^ Sweetow R, Palmer CV (July 2005). "Efficacy of individual auditory training in adults: a systematic review of the evidence". Journal of the American Academy of Audiology. 16 (7): 494–504. doi:10.3766/jaaa.16.7.9. PMID 16295236. NCBI NBK71453.
  6. ^ Naples JG, Ruckenstein MJ (February 2020). "Cochlear Implant". Otolaryngologic Clinics of North America. 53 (1): 87–102. doi:10.1016/j.otc.2019.09.004. PMID 31677740. S2CID 207890377.
  7. ^ Clark GM (April 2015). "The multi-channel cochlear implant: multi-disciplinary development of electrical stimulation of the cochlea and the resulting clinical benefit". Hearing Research. 322: 4–13. doi:10.1016/j.heares.2014.08.002. PMID 25159273.
  8. ^ Shannon RV (February 2012). "Advances in auditory prostheses". Current Opinion in Neurology. 25 (1): 61–66. doi:10.1097/WCO.0b013e32834ef878. PMC 4123811. PMID 22157109.
  9. ^ Blamey P, Artieres F, Başkent D, Bergeron F, Beynon A, Burke E, et al. (2013). "Factors affecting auditory performance of postlinguistically deaf adults using cochlear implants: an update with 2251 patients" (PDF). Audiology & Neuro-Otology. 18 (1): 36–47. doi:10.1159/000343189. PMID 23095305. S2CID 4668675.
  10. ^ Başkent D, Gaudrain E, Tamati TN, Wagner A (2016). "Perception and Psychoacoustics of Speech in Cochlear Implant Users". In Cacace AT, de Kleine E, Holt AG, van Dijk P (eds.). Scientific Foundations of Audiology: Perspectives from Physics, Biology, Modeling, and Medicine. Plural Publishing. pp. 285–319. hdl:11370/eef54b8f-af38-4c58-b14d-3ee376412a08. ISBN 978-1-59756-652-0. S2CID 33984881.
  11. ^ Pisoni DB, Kronenberger WG, Harris MS, Moberly AC (December 2017). "Three challenges for future research on cochlear implants". World Journal of Otorhinolaryngology–Head & Neck Surgery. 3 (4): 240–254. doi:10.1016/j.wjorl.2017.12.010. PMC 5956139. PMID 29780970.
  12. ^ "What Are Cochlear Implants for Hearing? | NIDCD". www.nidcd.nih.gov. 2024-05-06. Retrieved 2024-05-24.