A Meta-Analysis of Bilateral Cochlear Implants
As more implant centers are performing bilateral cochlear implants, Johnston et al (2009) undertook a critical and comprehensive examination of the literature published between 2000 and January 2008 to evaluate the effectiveness of bilateral (sequential and/or simultaneous) cochlear implantation (BICI).
Twenty-nine articles met the inclusion criteria. Fifteen of the 29 articles were authored in the United States, seven were from the EU, three were from Canada, and four from Australia. BICI has gained more interest recently, evidenced by the fact that 16 of the 29 studies were from 2007 and January 2008.
Sound localization and speech recognition in noise appear improved via BICI. Additionally, if the second CI is implanted early, improved morphology is evident across evoked potentials. Indeed, children implanted early with little (or no) time between the first and second CI show the greatest improvements in speech understanding in noise and localization ability.
When comparing similar studies of speech recognition in noise and localization ability, BICI children appear to perform more like normally hearing children than do children with unilateral CIs.
For More Information, References, and Recommendations:
Johnston JC, Durieux-Smith A, Angus D, O' Connor A, Fitzpatrick E. (2009) Bilateral Paediatric Cochlear Implants: A Critical Review. International Journal of Audiology (48)9:601-617.