Cochlear implants raise word comprehension from zero to 70-90 percent with retraining

Evidence

Such implants began with only one electrode temporarily inserted in the early 1960s, at the clinic of Dr. William House in Los Angeles. The scientific world was quite skeptical of the idea that an implant in a structure that is intricate down to the molecular level, as we have seen, could lead to better hearing. It is now well established that the implant often leads to truly profound improvements. Word comprehension typically increases from 0% to 70% to 90%, after retraining. No one claims the world sounds as it once did to adults who have lost their hearing; music especially is quite different, although according to some still possible to enjoy. — Eric J. Heller, Why You Hear What You Hear- An…, 1966