Binaural cochlear implantation: comparison of 3M/House and Nucleus 22 devices with evidence of sensory integration.

Direct comparison of the efficacy of cochlear implant designs has been difficult for several reasons. There have been wide variations in patients implanted and many differences in testing protocols for each device. In most instances, even a single patient may have unequal degrees of pathology and duration of deafness in the two ears. Implantation of a 3M/House device in the left ear and a Nucleus 22 device in the right ear of a 55-year-old woman, deafened to a similar degree and simultaneously in both ears by streptomycin, allows an opportunity to compare function under presumably similar circumstances. The Nucleus 22 cochlear implant was superior in this case in providing speech discrimination. Perhaps of greater interest, however, is evidence of a binaural effect. Presumably, central integration of sensory stimuli presented through two dissimilar processing strategies resulted in enhanced function on certain measures.