Strelnikov et al (2011) used positron emission tomography (PET) to evaluate five people with bilateral cochlear implants (CIs) and five people with normal hearing (NH). Each subject was tasked via monaural and binaural sound presentations to distinguish words from non-words.
Generally, when CI subjects had binaural presentations, their brain activation patterns were similar to NH subjects. The authors note that monaural stimulation facilitated greater differences between CI and NH subjects, as a “higher computational load” is present when monaural stimulation is presented to CI subjects. Specifically, because phonological information delivered via CIs is degraded, more processing work must be accomplished by the brain when monaural CI pathways are chosen.
Strelnikov et al conclude that binaural CIs allow brain plasticity mechanisms to lead to adaptive mechanisms similar to those found in NH subjects.
For More Information, References, and Recommendations
Eggermont J. (2008) The Role of Sound in Adult and Developmental Auditory Cortical Plasticity. Ear & Hearing 29(6).
Strelnikov K, Rouger J, Eter E, Lagleyre S, Fraysse B, Demonet JF, Barone P, Deguine O. (2011) Binaural Stimulation Through Cochlear Implants in Postlingual Deafness – A Positron Emission Tomographic Study of Word Recognition. Otology & Neurotology 32(8):1210-1217.