Why does a cochlear implant take months to sound like speech? · Grey Matter

The implant delivers a handful of frequency bands where a healthy ear sends the detailed output of thousands of hair cells, and each contact may sit at a slightly different place in the cochlea from the pitch its band is meant to carry.

Why does a cochlear implant take months to sound like speech?

The implant delivers a handful of frequency bands where a healthy ear sends the detailed output of thousands of hair cells, and each contact may sit at a slightly different place in the cochlea from the pitch its band is meant to carry. The auditory cortex therefore receives a coarse and partly shifted signal, and at switch-on many people describe what they hear as beeps or robotic voices. Over months of listening the cortex learns to map those patterns onto speech, which is why results depend on daily use and why implanted adults end up recognising most sentences in quiet.